less part 1 of 2
sources-request at panda.UUCP
sources-request at panda.UUCP
Wed Feb 12 09:30:56 AEST 1986
Mod.sources: Volume 3, Issue 120
Submitted by: ihnp4!nsc!nsc-pdc!rgb (Robert Bond)
Here is the last distribution of less made by Mark Nudelman to net.sources
before he left National Semiconductor. Since it is taking so long for him
to get back on the net, and because lots of folks did not get part 2
of the last distribution, we have decided to submit less to mod.sources.
Mark is still promising to return to the net Real Soon Now.
#!/bin/sh-----cut here-----cut here-----cut here-----cut here-----
# shar: Shell Archiver
# Run the following text with /bin/sh to create:
# INSTALLATION
# less.l
# makefile.bsd41
# makefile.bsd42
# makefile.sys5
# makefile.xen
# funcs.h
# less.h
# position.h
# mkfuncs.awk
# main.c
# option.c
# prim.c
echo shar: extracting INSTALLATION
cat - << \SHAR_EOF > INSTALLATION
This is the distribution of "less", a paginator similar to "more" or "pg".
The manual page is in less.l.
INSTALLATION:
1. Move the distributed source to its own directory and
unpack it by running "sh" on the distribution file,
if you have not already done so.
2. If your system is System V:
cp makefile.sys5 makefile
If your system is Berkeley 4.2bsd:
cp makefile.bsd42 makefile
If your system is Berkeley 4.1bsd:
cp makefile.bsd41 makefile
If your system is Xenix 3.0:
cp makefile.xen makefile
Otherwise, edit the makefile to make the
system parameters match your system.
These features are selectable at compile time:
shell escapes (SHELL_ESCAPE)
editor invocation (EDITOR)
alternate error message handling (ONLY_RETURN)
If you want to have any of these features,
edit the makefile appropriately.
(If you do not include either SHELL_ESCAPE or EDITOR,
you may wish to edit the manual page "less.l" to remove
the references to the "!" and/or "v" commands.)
3. Type "make" and watch the fun.
4. If the make succeeds, it will generate a program "less"
in your current directory. Test the generated program.
5. When satisfied that it works, if you wish to install it
in a public place, edit the makefile so that INSTALL_LESS
and INSTALL_MAN are the proper filenames.
Then type "make install".
If you have any problems building or running "less",
you may mail to the author via USENET at:
...!tektronix!reed!nsc-pdc!mark
or ...!ihnp4!nsc!nsc-pdc!mark
Note to hackers: comments noting possible improvements are enclosed
in double curly brackets {{ like this }}.
SHAR_EOF
echo shar: extracting less.l
cat - << \SHAR_EOF > less.l
.TH LESS l
.SH NAME
less \- opposite of more
.SH SYNOPSIS
.B "less [-cdepstwmMqQuU] [-h\fIn\fB] [-b[fp]\fIn\fB] [-x\fIn\fB] [+\fIcmd\fB] [\fIname\fB] ..."
.SH DESCRIPTION
.I Less
is a program similar to
.I more
(1), but which allows backwards movement
in the file as well as forward movement.
Also,
.I less
does not have to read the entire input file before starting,
so with large input files it starts up faster than text editors like
.I vi
(1).
.I Less
uses termcap, so it can run on a variety of terminals.
There is even limited support for hardcopy terminals.
(On a hardcopy terminal, lines which should be printed at the top
of the screen are prefixed with an up-arrow.)
.PP
Commands are based on both
.I more
and
.I vi.
Commands may be preceeded by a decimal number,
called N in the descriptions below.
The number is used by some commands, as indicated.
.SH COMMANDS
.IP h
Help: display a summary of these commands.
If you forget all the other commands, remember this one.
.PP
.IP SPACE
Scroll forward N lines, default one screen.
If N is more than the screen size, only one screenful is displayed.
.PP
.IP f
Same as SPACE.
.PP
.IP b
Scroll backward N lines, default one screen.
If N is more than the screen size, only one screenful is displayed.
.PP
.IP RETURN
Scroll forward N lines, default 1.
If N is more than the screen size, the entire N lines are displayed.
.PP
.IP e
Same as RETURN.
.PP
.IP j
Also the same as RETURN.
.PP
.IP y
Scroll backward N lines, default 1.
If N is more than the screen size, the entire N lines are displayed.
.IP k
Same as y.
.PP
.IP d
Scroll forward N lines, default 10.
If N is specified, it becomes the new default for all d and u commands.
.PP
.IP u
Scroll backward N lines, default 10.
If N is specified, it becomes the new default for all d and u commands.
.PP
.IP r
Repaint the screen.
.PP
.IP R
Repaint the screen, discarding any buffered input.
Useful if the file is changing while it is being viewed.
.PP
.IP g
Go to line N in the file, default 1 (beginning of file).
(Warning: this may be slow if N is large.)
.PP
.IP G
Go to line N in the file, default the end of the file.
(Warning: this may be slow if standard input,
rather than a file, is being read.)
.PP
.IP p
Go to a position N percent into the file.
N should be between 0 and 100.
(This is possible if standard input is being read,
but only if
.I less
has already read to the end of the file.
It is always fast, but not always useful.)
.PP
.IP %
Same as p.
.PP
.IP m
Followed by any lowercase letter, marks the current position with that letter.
.PP
.IP "'"
Followed by any lowercase letter, returns to the position which
was previously marked with that letter.
All marks are lost when a new file is examined.
.PP
.IP /pattern
Search forward in the file for the N-th occurence of the pattern.
N defaults to 1.
The pattern is a regular expression, as recognized by
.I ed.
The search starts at the second line displayed
(but see the -t option, which changes this).
.PP
.IP ?pattern
Search backward in the file for the N-th occurence of the pattern.
The search starts at the line immediately before the top line displayed.
.PP
.IP n
Repeat previous search, for N-th occurence of the last pattern.
.PP
.IP E [filename]
Examine a new file.
If the filename is missing, the "current" file (see the N and P commands
below) from the list of files in the command line is re-examined.
.PP
.IP N
Examine the next file (from the list of files given in the command line).
If a number N is specified (not to be confused with the command N),
the N-th next file is examined.
.PP
.IP P
Examine the previous file.
If a number N is specified, the N-th previous file is examined.
.PP
.IP =
Prints the name of the file being viewed
and the byte offset of the bottom line being displayed.
If possible, it also prints the length of the file
and the percent of the file above the last displayed line.
.PP
.IP \-
Followed by one of the command line option letters (see below),
this will toggle the setting of that option
and print a message describing the new setting.
.PP
.IP V
Prints the version number of
.I less
being run.
.PP
.IP q
Exits
.I less.
.PP
The following
two
commands may or may not be valid, depending on your particular installation.
.PP
.IP v
Invokes an editor to edit the current file being viewed.
The editor is taken from the environment variable EDITOR,
or defaults to "vi".
.PP
.IP "! shell-command"
Invokes a shell to run the shell-command given.
.PP
.SH OPTIONS
Command line options are described below.
Options are also taken from the environment variable "LESS".
(The environment variable is parsed before the command line,
so command line options override the LESS environment variable.
Options may be changed while
.I less
is running via the "\-" command.)
For example, if you like
more-style prompting, to avoid typing "less -m ..." each time
.I less
is invoked, you might tell
.I csh:
.sp
setenv LESS m
.sp
or if you use
.I sh:
.sp
LESS=m; export LESS
.IP -s
The -s flag causes
consecutive blank lines to be squeezed into a single blank line.
This is useful when viewing
.I nroff
output.
.IP -t
Normally, forward searches start just after
the top displayed line (that is, at the second displayed line).
Thus forward searches include the currently displayed screen.
The -t command line option causes forward searches to start
just after the bottom line displayed,
thus skipping the currently displayed screen.
.IP -m
Normally,
.I less
prompts with a colon.
The -m command line option causes
.I less
to prompt verbosely like
.I more,
printing the file name and percent into the file.
.IP -M
The -M command line option causes
.I less
to prompt even more verbosely than
.I more.
.IP -q
Normally, if an attempt is made to scroll past the end of the file
or before the beginning of the file, the terminal bell is rung to
indicate this fact.
The -q command line option tells
.I less
not to ring the bell at such times.
If the terminal has a "visual bell", it is used instead.
.IP -Q
Even if -q is given,
.I less
will ring the bell on certain other errors,
such as typing an invalid character.
The -Q command line option tells
.I less
to be quiet all the time; that is, never ring the terminal bell.
If the terminal has a "visual bell", it is used instead.
.IP -e
Normally the only way to exit less is via the "q" command.
The -e command line option tells less to automatically exit
the second time it reaches end-of-file.
.IP -u
If the -u command line option is given,
backspaces are treated as printable characters;
that is, they are sent to the terminal when they appear in the input.
.IP -U
If the -U command line option is given,
backspaces are printed as the two character sequence "^H".
If neither -u nor -U is given,
backspaces which appear adjacent to an underscore character
are treated specially:
the underlined text is displayed
using the terminal's hardware underlining capability.
.IP -w
Normally,
.I less
uses a tilde character to represent lines past the end of the file.
The -w option causes blank lines to be used instead.
.IP -d
Normally,
.I less
will complain if the terminal is dumb; that is, lacks some important capability,
such as the ability to clear the screen or scroll backwards.
The -d flag suppresses this complaint
(but does not otherwise change the behavior of the program on a dumb terminal).
.IP -p
Normally,
.I less
will repaint the screen by scrolling from the bottom of the screen.
If the -p flag is set, when
.I less
needs to change the entire display, it will clear the screen
and paint from the top line down.
.IP -h
Normally,
.I less
will scroll backwards when backwards movement is necessary.
The -h option specifies a maximum number of lines to scroll backwards.
If it is necessary to move backwards more than this many lines,
the screen is repainted in a forward direction.
(If the terminal does not have the ability to scroll
backwards, -h0 is implied.)
.IP -x
The -x\fIn\fR command line option sets tab stops every \fIn\fR positions.
The default for \fIn\fR is 8.
.IP -b
The -b\fIn\fR command line option tells
.I less
to use a non-standard buffer size.
There are two standard (default) buffer sizes,
one is used when a file is being read and the other
when a pipe (standard input) is being read.
The current defaults are 5 buffers for files and 12 for pipes.
(Buffers are 1024 bytes.)
The number \fIn\fR specifies a different number of buffers to use.
The -b may be followed by "f", in which case only
the file default is changed, or by "p" in which case only the
pipe default is changed. Otherwise, both are changed.
.IP -c
Normally, when data is read by
.I less,
it is scanned to ensure that bit 7 (the high order bit) is turned off in
each byte read, and to ensure that there are no null (zero) bytes in
the data (null bytes are turned into "@" characters).
If the data is known to be "clean",
the -c command line option will tell
.I less
to skip this checking, causing an imperceptible speed improvement.
(However, if the data is not "clean", unpredicatable results may occur.)
.IP +
If a command line option begins with \fB+\fR,
the remainder of that option is taken to be an initial command to
.I less.
For example, +G tells
.I less
to start at the end of the file rather than the beginning,
and +/xyz tells it to start at the first occurence of "xyz" in the file.
As a special case, +<number> acts like +<number>g;
that is, it starts the display at the specified line number
(however, see the caveat under the "g" command above).
If the option starts with \fB++\fR, the initial command applies to
every file being viewed, not just the first one.
.SH BUGS
When used on standard input (rather than a file), you can move
backwards only a finite amount, corresponding to that portion
of the file which is still buffered.
SHAR_EOF
echo shar: extracting makefile.bsd41
cat - << \SHAR_EOF > makefile.bsd41
# Makefile for "less"
#
# Invoked as:
# make all
# or make install
# Plain "make" is equivalent to "make all".
#
# If you add or delete functions, remake funcs.h by doing:
# make newfuncs
# This depends on the coding convention of function headers looking like:
# " \t public <function-type> \n <function-name> ( ... ) "
#
# Also provided:
# make lint # Runs "lint" on all the sources.
# make clean # Removes "less" and the .o files.
# make clobber # Pretty much the same as make "clean".
##########################################################################
# System-specific parameters
##########################################################################
# Define XENIX if running under XENIX 3.0
XENIX = 0
# VOID is 1 if your C compiler supports the "void" type,
# 0 if it does not.
VOID = 1
# off_t is the type which lseek() returns.
# It is also the type of lseek()'s second argument.
off_t = long
# TERMIO is 1 if your system has /usr/include/termio.h.
# This is normally the case for System 5.
# If TERMIO is 0 your system must have /usr/include/sgtty.h.
# This is normally the case for BSD.
TERMIO = 0
# SIGSETMASK is 1 if your system has the sigsetmask() call.
# This is normally the case only for BSD 4.2,
# not for BSD 4.1 or System 5.
SIGSETMASK = 0
##########################################################################
# Optional and semi-optional features
##########################################################################
# REGCMP is 1 if your system has the regcmp() function.
# This is normally the case for System 5.
# RECOMP is 1 if your system has the re_comp() function.
# This is normally the case for BSD.
# If neither is 1, pattern matching is supported, but without metacharacters.
REGCMP = 0
RECOMP = 1
# SHELL_ESCAPE is 1 if you wish to allow shell escapes.
# (This is possible only if your system supplies the system() function.)
SHELL_ESCAPE = 0
# EDITOR is 1 if you wish to allow editor invocation (the "v" command).
# (This is possible only if your system supplies the system() function.)
# EDIT_PGM is the name of the (default) editor to be invoked.
EDITOR = 0
EDIT_PGM = /usr/ucb/vi
# ONLY_RETURN is 1 if you want RETURN to be the only input which
# will continue past an error message.
# Otherwise, any key will continue past an error message.
ONLY_RETURN = 0
##########################################################################
# Compilation environment.
##########################################################################
# LIBS is the list of libraries needed.
LIBS = -ltermcap
# INSTALL_LESS is a list of the public versions of less.
# INSTALL_MAN is a list of the public versions of the manual page.
INSTALL_LESS = /usr/local/less
INSTALL_MAN = /usr/man/manl/less.l
# OPTIM is passed to the compiler and the loader.
# It is normally "-O" but may be, for example, "-g".
OPTIM = -O
##########################################################################
# Files
##########################################################################
SRC1 = main.c option.c prim.c
SRC2 = ch.c position.c input.c output.c screen.c \
prompt.c line.c signal.c help.c ttyin.c command.c version.c
SRC = $(SRC1) $(SRC2)
OBJ = main.o option.o prim.o ch.o position.o input.o output.o screen.o \
prompt.o line.o signal.o help.o ttyin.o command.o version.o
##########################################################################
# Rules
##########################################################################
DEFS = "-DTERMIO=$(TERMIO)" \
"-DSIGSETMASK=$(SIGSETMASK)" \
"-Doff_t=$(off_t)" "-DVOID=$(VOID)" \
"-DREGCMP=$(REGCMP)" "-DRECOMP=$(RECOMP)" \
"-DSHELL_ESCAPE=$(SHELL_ESCAPE)" \
"-DEDITOR=$(EDITOR)" "-DEDIT_PGM=\"$(EDIT_PGM)\"" \
"-DONLY_RETURN=$(ONLY_RETURN)" \
"-DXENIX=$(XENIX)"
CFLAGS = $(OPTIM) $(DEFS)
all: less
less: $(OBJ)
cc $(OPTIM) -o less $(OBJ) $(LIBS)
install: install_man install_less
install_man: less.l
for f in $(INSTALL_MAN); do rm -f $$f; cp less.l $$f; done
touch install_man
install_less: less
for f in $(INSTALL_LESS); do rm -f $$f; cp less $$f; done
touch install_less
$(OBJ): less.h funcs.h
lint:
lint -hp $(DEFS) $(SRC)
newfuncs:
mv funcs.h funcs.h.OLD
awk -f mkfuncs.awk $(SRC) >funcs.h
clean:
rm -f $(OBJ) less
clobber:
rm -f *.o less install_less install_man
shar:
shar -v INSTALLATION less.l makefile.* *.h *.awk $(SRC1) > less.shar.a
shar -v $(SRC2) > less.shar.b
SHAR_EOF
echo shar: extracting makefile.bsd42
cat - << \SHAR_EOF > makefile.bsd42
# Makefile for "less"
#
# Invoked as:
# make all
# or make install
# Plain "make" is equivalent to "make all".
#
# If you add or delete functions, remake funcs.h by doing:
# make newfuncs
# This depends on the coding convention of function headers looking like:
# " \t public <function-type> \n <function-name> ( ... ) "
#
# Also provided:
# make lint # Runs "lint" on all the sources.
# make clean # Removes "less" and the .o files.
# make clobber # Pretty much the same as make "clean".
##########################################################################
# System-specific parameters
##########################################################################
# Define XENIX if running under XENIX 3.0
XENIX = 0
# VOID is 1 if your C compiler supports the "void" type,
# 0 if it does not.
VOID = 1
# off_t is the type which lseek() returns.
# It is also the type of lseek()'s second argument.
off_t = long
# TERMIO is 1 if your system has /usr/include/termio.h.
# This is normally the case for System 5.
# If TERMIO is 0 your system must have /usr/include/sgtty.h.
# This is normally the case for BSD.
TERMIO = 0
# SIGSETMASK is 1 if your system has the sigsetmask() call.
# This is normally the case only for BSD 4.2,
# not for BSD 4.1 or System 5.
SIGSETMASK = 1
##########################################################################
# Optional and semi-optional features
##########################################################################
# REGCMP is 1 if your system has the regcmp() function.
# This is normally the case for System 5.
# RECOMP is 1 if your system has the re_comp() function.
# This is normally the case for BSD.
# If neither is 1, pattern matching is supported, but without metacharacters.
REGCMP = 0
RECOMP = 1
# SHELL_ESCAPE is 1 if you wish to allow shell escapes.
# (This is possible only if your system supplies the system() function.)
SHELL_ESCAPE = 0
# EDITOR is 1 if you wish to allow editor invocation (the "v" command).
# (This is possible only if your system supplies the system() function.)
# EDIT_PGM is the name of the (default) editor to be invoked.
EDITOR = 0
EDIT_PGM = /usr/ucb/vi
# ONLY_RETURN is 1 if you want RETURN to be the only input which
# will continue past an error message.
# Otherwise, any key will continue past an error message.
ONLY_RETURN = 0
##########################################################################
# Compilation environment.
##########################################################################
# LIBS is the list of libraries needed.
LIBS = -ltermcap
# INSTALL_LESS is a list of the public versions of less.
# INSTALL_MAN is a list of the public versions of the manual page.
INSTALL_LESS = /usr/local/less
INSTALL_MAN = /usr/man/manl/less.l
# OPTIM is passed to the compiler and the loader.
# It is normally "-O" but may be, for example, "-g".
OPTIM = -O
##########################################################################
# Files
##########################################################################
SRC1 = main.c option.c prim.c
SRC2 = ch.c position.c input.c output.c screen.c \
prompt.c line.c signal.c help.c ttyin.c command.c version.c
SRC = $(SRC1) $(SRC2)
OBJ = main.o option.o prim.o ch.o position.o input.o output.o screen.o \
prompt.o line.o signal.o help.o ttyin.o command.o version.o
##########################################################################
# Rules
##########################################################################
DEFS = "-DTERMIO=$(TERMIO)" \
"-DSIGSETMASK=$(SIGSETMASK)" \
"-Doff_t=$(off_t)" "-DVOID=$(VOID)" \
"-DREGCMP=$(REGCMP)" "-DRECOMP=$(RECOMP)" \
"-DSHELL_ESCAPE=$(SHELL_ESCAPE)" \
"-DEDITOR=$(EDITOR)" "-DEDIT_PGM=\"$(EDIT_PGM)\"" \
"-DONLY_RETURN=$(ONLY_RETURN)" \
"-DXENIX=$(XENIX)"
CFLAGS = $(OPTIM) $(DEFS)
all: less
less: $(OBJ)
cc $(OPTIM) -o less $(OBJ) $(LIBS)
install: install_man install_less
install_man: less.l
for f in $(INSTALL_MAN); do rm -f $$f; cp less.l $$f; done
touch install_man
install_less: less
for f in $(INSTALL_LESS); do rm -f $$f; cp less $$f; done
touch install_less
$(OBJ): less.h funcs.h
lint:
lint -hp $(DEFS) $(SRC)
newfuncs:
mv funcs.h funcs.h.OLD
awk -f mkfuncs.awk $(SRC) >funcs.h
clean:
rm -f $(OBJ) less
clobber:
rm -f *.o less install_less install_man
shar:
shar -v INSTALLATION less.l makefile.* *.h *.awk $(SRC1) > less.shar.a
shar -v $(SRC2) > less.shar.b
SHAR_EOF
echo shar: extracting makefile.sys5
cat - << \SHAR_EOF > makefile.sys5
# Makefile for "less"
#
# Invoked as:
# make all
# or make install
# Plain "make" is equivalent to "make all".
#
# If you add or delete functions, remake funcs.h by doing:
# make newfuncs
# This depends on the coding convention of function headers looking like:
# " \t public <function-type> \n <function-name> ( ... ) "
#
# Also provided:
# make lint # Runs "lint" on all the sources.
# make clean # Removes "less" and the .o files.
# make clobber # Pretty much the same as make "clean".
##########################################################################
# System-specific parameters
##########################################################################
# Define XENIX if running under XENIX 3.0
XENIX = 0
# VOID is 1 if your C compiler supports the "void" type,
# 0 if it does not.
VOID = 1
# off_t is the type which lseek() returns.
# It is also the type of lseek()'s second argument.
off_t = long
# TERMIO is 1 if your system has /usr/include/termio.h.
# This is normally the case for System 5.
# If TERMIO is 0 your system must have /usr/include/sgtty.h.
# This is normally the case for BSD.
TERMIO = 1
# SIGSETMASK is 1 if your system has the sigsetmask() call.
# This is normally the case only for BSD 4.2,
# not for BSD 4.1 or System 5.
SIGSETMASK = 0
##########################################################################
# Optional and semi-optional features
##########################################################################
# REGCMP is 1 if your system has the regcmp() function.
# This is normally the case for System 5.
# RECOMP is 1 if your system has the re_comp() function.
# This is normally the case for BSD.
# If neither is 1, pattern matching is supported, but without metacharacters.
REGCMP = 1
RECOMP = 0
# SHELL_ESCAPE is 1 if you wish to allow shell escapes.
# (This is possible only if your system supplies the system() function.)
SHELL_ESCAPE = 0
# EDITOR is 1 if you wish to allow editor invocation (the "v" command).
# (This is possible only if your system supplies the system() function.)
# EDIT_PGM is the name of the (default) editor to be invoked.
EDITOR = 0
EDIT_PGM = /usr/ucb/vi
# ONLY_RETURN is 1 if you want RETURN to be the only input which
# will continue past an error message.
# Otherwise, any key will continue past an error message.
ONLY_RETURN = 0
##########################################################################
# Compilation environment.
##########################################################################
# LIBS is the list of libraries needed.
LIBS = -lcurses -lPW
# INSTALL_LESS is a list of the public versions of less.
# INSTALL_MAN is a list of the public versions of the manual page.
INSTALL_LESS = /usr/lbin/less
INSTALL_MAN = /usr/man/manl/less.l
# OPTIM is passed to the compiler and the loader.
# It is normally "-O" but may be, for example, "-g".
OPTIM = -O
##########################################################################
# Files
##########################################################################
SRC1 = main.c option.c prim.c
SRC2 = ch.c position.c input.c output.c screen.c \
prompt.c line.c signal.c help.c ttyin.c command.c version.c
SRC = $(SRC1) $(SRC2)
OBJ = main.o option.o prim.o ch.o position.o input.o output.o screen.o \
prompt.o line.o signal.o help.o ttyin.o command.o version.o
##########################################################################
# Rules
##########################################################################
DEFS = "-DTERMIO=$(TERMIO)" \
"-DSIGSETMASK=$(SIGSETMASK)" \
"-Doff_t=$(off_t)" "-DVOID=$(VOID)" \
"-DREGCMP=$(REGCMP)" "-DRECOMP=$(RECOMP)" \
"-DSHELL_ESCAPE=$(SHELL_ESCAPE)" \
"-DEDITOR=$(EDITOR)" "-DEDIT_PGM=\"$(EDIT_PGM)\"" \
"-DONLY_RETURN=$(ONLY_RETURN)" \
"-DXENIX=$(XENIX)"
CFLAGS = $(OPTIM) $(DEFS)
all: less
less: $(OBJ)
cc $(OPTIM) -o less $(OBJ) $(LIBS)
install: install_man install_less
install_man: less.l
for f in $(INSTALL_MAN); do rm -f $$f; cp less.l $$f; done
touch install_man
install_less: less
for f in $(INSTALL_LESS); do rm -f $$f; cp less $$f; done
touch install_less
$(OBJ): less.h funcs.h
lint:
lint -hp $(DEFS) $(SRC)
newfuncs:
mv funcs.h funcs.h.OLD
awk -f mkfuncs.awk $(SRC) >funcs.h
clean:
rm -f $(OBJ) less
clobber:
rm -f *.o less install_less install_man
shar:
shar -v INSTALLATION less.l makefile.* *.h *.awk $(SRC1) > less.shar.a
shar -v $(SRC2) > less.shar.b
SHAR_EOF
echo shar: extracting makefile.xen
cat - << \SHAR_EOF > makefile.xen
# Makefile for "less"
#
# Invoked as:
# make all
# or make install
# Plain "make" is equivalent to "make all".
#
# If you add or delete functions, remake funcs.h by doing:
# make newfuncs
# This depends on the coding convention of function headers looking like:
# " \t public <function-type> \n <function-name> ( ... ) "
#
# Also provided:
# make lint # Runs "lint" on all the sources.
# make clean # Removes "less" and the .o files.
# make clobber # Pretty much the same as make "clean".
##########################################################################
# System-specific parameters
##########################################################################
# Define XENIX if running under XENIX 3.0
XENIX = 1
# VOID is 1 if your C compiler supports the "void" type,
# 0 if it does not.
VOID = 1
# off_t is the type which lseek() returns.
# It is also the type of lseek()'s second argument.
off_t = long
# TERMIO is 1 if your system has /usr/include/termio.h.
# This is normally the case for System 5.
# If TERMIO is 0 your system must have /usr/include/sgtty.h.
# This is normally the case for BSD.
TERMIO = 1
# SIGSETMASK is 1 if your system has the sigsetmask() call.
# This is normally the case only for BSD 4.2,
# not for BSD 4.1 or System 5.
SIGSETMASK = 0
##########################################################################
# Optional and semi-optional features
##########################################################################
# REGCMP is 1 if your system has the regcmp() function.
# This is normally the case for System 5.
# RECOMP is 1 if your system has the re_comp() function.
# This is normally the case for BSD.
# If neither is 1, pattern matching is supported, but without metacharacters.
REGCMP = 1
RECOMP = 0
# SHELL_ESCAPE is 1 if you wish to allow shell escapes.
# (This is possible only if your system supplies the system() function.)
SHELL_ESCAPE = 0
# EDITOR is 1 if you wish to allow editor invocation (the "v" command).
# (This is possible only if your system supplies the system() function.)
# EDIT_PGM is the name of the (default) editor to be invoked.
EDITOR = 0
EDIT_PGM = /usr/ucb/vi
# ONLY_RETURN is 1 if you want RETURN to be the only input which
# will continue past an error message.
# Otherwise, any key will continue past an error message.
ONLY_RETURN = 0
##########################################################################
# Compilation environment.
##########################################################################
# LIBS is the list of libraries needed.
LIBS = -lcurses -ltermlib
# INSTALL_LESS is a list of the public versions of less.
# INSTALL_MAN is a list of the public versions of the manual page.
INSTALL_LESS = /usr/lbin/less
INSTALL_MAN = /usr/man/manl/less.l
# OPTIM is passed to the compiler and the loader.
# It is normally "-O" but may be, for example, "-g".
OPTIM = -O
##########################################################################
# Files
##########################################################################
SRC1 = main.c option.c prim.c
SRC2 = ch.c position.c input.c output.c screen.c \
prompt.c line.c signal.c help.c ttyin.c command.c version.c
SRC = $(SRC1) $(SRC2)
OBJ = main.o option.o prim.o ch.o position.o input.o output.o screen.o \
prompt.o line.o signal.o help.o ttyin.o command.o version.o
##########################################################################
# Rules
##########################################################################
DEFS = "-DTERMIO=$(TERMIO)" \
"-DSIGSETMASK=$(SIGSETMASK)" \
"-Doff_t=$(off_t)" "-DVOID=$(VOID)" \
"-DREGCMP=$(REGCMP)" "-DRECOMP=$(RECOMP)" \
"-DSHELL_ESCAPE=$(SHELL_ESCAPE)" \
"-DEDITOR=$(EDITOR)" "-DEDIT_PGM=\"$(EDIT_PGM)\"" \
"-DONLY_RETURN=$(ONLY_RETURN)" \
"-DXENIX=$(XENIX)"
CFLAGS = $(OPTIM) $(DEFS)
all: less
less: $(OBJ)
cc $(OPTIM) -o less $(OBJ) $(LIBS)
install: install_man install_less
install_man: less.l
for f in $(INSTALL_MAN); do rm -f $$f; cp less.l $$f; done
touch install_man
install_less: less
for f in $(INSTALL_LESS); do rm -f $$f; cp less $$f; done
touch install_less
$(OBJ): less.h funcs.h
lint:
lint -hp $(DEFS) $(SRC)
newfuncs:
mv funcs.h funcs.h.OLD
awk -f mkfuncs.awk $(SRC) >funcs.h
clean:
rm -f $(OBJ) less
clobber:
rm -f *.o less install_less install_man
shar:
shar -v INSTALLATION less.l makefile.* *.h *.awk $(SRC1) > less.shar.a
shar -v $(SRC2) > less.shar.b
SHAR_EOF
echo shar: extracting funcs.h
cat - << \SHAR_EOF > funcs.h
public void edit ();
public void next_file ();
public void prev_file ();
public void quit ();
public void init_option ();
public void toggle_option ();
public void scan_option ();
public void forward ();
public void backward ();
public void repaint ();
public void jump_forw ();
public void jump_back ();
public void jump_percent ();
public void jump_loc ();
public void init_mark ();
public void setmark ();
public void gomark ();
public void search ();
public int ch_seek ();
public int ch_end_seek ();
public POSITION ch_length ();
public POSITION ch_tell ();
public int ch_forw_get ();
public int ch_back_get ();
public void ch_init ();
public POSITION position ();
public void add_forw_pos ();
public void add_back_pos ();
public void pos_clear ();
public int onscreen ();
public POSITION forw_line ();
public POSITION back_line ();
public void put_line ();
public int control_char ();
public int carat_char ();
public void flush ();
public void dropout ();
public void putc ();
public void puts ();
public void error ();
public int error_width ();
public void raw_mode ();
public void get_term ();
public void init ();
public void deinit ();
public void home ();
public void add_line ();
public void lower_left ();
public void bell ();
public void vbell ();
public void clear ();
public void clear_eol ();
public void so_enter ();
public void so_exit ();
public void ul_enter ();
public void ul_exit ();
public void backspace ();
public void putbs ();
public char * eq_message ();
public char * pr_string ();
public void prewind ();
public int pappend ();
public POSITION forw_raw_line ();
public POSITION back_raw_line ();
public void init_signals ();
public void psignals ();
public void lsystem ();
public void help ();
public void open_getc ();
public int getc ();
public void commands ();
SHAR_EOF
echo shar: extracting less.h
cat - << \SHAR_EOF > less.h
/*
* Standard include file for "less".
*/
/*
* Language details.
*/
#if !VOID
#define void int
#endif
#define public /* PUBLIC FUNCTION */
/*
* Special types and constants.
*/
typedef long POSITION;
/*
* {{ Warning: if POSITION is changed to other than "long",
* you may have to change some of the printfs which use "%ld"
* to print a variable of type POSITION. }}
*/
#define END_POSITION ((POSITION)(-2))
#define NULL_POSITION ((POSITION)(-1))
#define EOF (0)
#define NULL (0)
/* How quiet should we be? */
#define NOT_QUIET 0 /* Ring bell at eof and for errors */
#define LITTLE_QUIET 1 /* Ring bell only for errors */
#define VERY_QUIET 2 /* Never ring bell */
/* How should we prompt? */
#define PR_SHORT 0 /* Prompt with colon */
#define PR_MEDIUM 1 /* Prompt with message */
#define PR_LONG 2 /* Prompt with longer message */
/* How should we handle backspaces? */
#define BS_UNDERLINE 0 /* Underlining converted to underline mode */
#define BS_NORMAL 1 /* \b treated as normal char; actually output */
#define BS_CONTROL 2 /* \b treated as control char; prints as ^H */
/* Flag to eq_message() telling what to put in the message */
#define MNAME 001 /* File name */
#define MOF 002 /* "file x of y" */
#define MBYTE 004 /* "byte x/y" */
#define MPCT 010 /* Percentage into the file */
/* Special chars used to tell put_line() to do something special */
#define UL_CHAR '\201' /* Enter underline mode */
#define UE_CHAR '\202' /* Exit underline mode */
#define CONTROL(c) ((c)&037)
#define SIGNAL(sig,func) signal(sig,func)
off_t lseek();
#include "funcs.h"
SHAR_EOF
echo shar: extracting position.h
cat - << \SHAR_EOF > position.h
/*
* Include file for interfacing to position.c modules.
*/
#define TOP 0
#define TOP_PLUS_ONE 1
#define BOTTOM -1
#define BOTTOM_PLUS_ONE -2
SHAR_EOF
echo shar: extracting mkfuncs.awk
cat - << \SHAR_EOF > mkfuncs.awk
BEGIN { FS="("; state = 0 }
/^ public/ { ftype = $0; state = 1 }
{ if (state == 1)
state = 2
else if (state == 2)
{ print ftype,$1,"();"; state = 0 }
}
SHAR_EOF
echo shar: extracting main.c
cat - << \SHAR_EOF > main.c
/*
* Entry point, initialization, miscellaneous routines.
*/
#include "less.h"
#include "position.h"
#include <setjmp.h>
public int ispipe;
public jmp_buf main_loop;
public char * first_cmd;
public char * every_first_cmd;
public int new_file;
public int is_tty;
public char current_file[128];
public int ac;
public char **av;
public int curr_ac;
#if EDITOR
public char * editor;
#endif
extern int file;
extern int nbufs;
extern int sigs;
extern int quit_at_eof;
extern int p_nbufs, f_nbufs;
extern int back_scroll;
extern int top_scroll;
extern int sc_height;
/*
* Edit a new file.
* Filename "-" means standard input.
* No filename means the "current" file, from the command line.
*/
public void
edit(filename)
char *filename;
{
register int f;
char message[100];
static int any_edited = 0;
static int hold_scroll = 0;
if (filename == NULL || *filename == '\0')
{
if (curr_ac >= ac)
{
error("No current file");
return;
}
filename = av[curr_ac];
}
if (strcmp(filename, "-") == 0)
f = 0; /* Standard input */
else if ((f = open(filename, 0)) < 0)
{
sprintf(message, "Cannot open %.*s",
error_width()-13, filename);
if (any_edited)
error(message);
else
{
puts(message);
hold_scroll = 1;
}
return;
}
if (isatty(f))
{
/*
* Not really necessary to call this an error,
* but if the control terminal (for commands)
* and the input file (for data) are the same,
* we get weird results at best.
*/
error("Can't take input from a terminal");
if (f > 0)
close(f);
return;
}
/*
* Close the current input file and set up to use the new one.
*/
if (file > 0)
close(file);
new_file = 1;
strcpy(current_file, filename);
ispipe = (f == 0);
file = f;
ch_init( (ispipe) ? p_nbufs : f_nbufs );
init_mark();
if (every_first_cmd != NULL)
first_cmd = every_first_cmd;
if (is_tty)
{
any_edited = 1;
if (hold_scroll)
{
/*
* Before erasing the screen contents,
* display the file name and ask for a keystroke.
*/
error(filename);
hold_scroll = 0;
}
if (first_cmd == NULL || *first_cmd == '\0')
{
/*
* Display the first screen.
*/
jump_back(1);
} else
{
/*
* The first_cmd will hopefully redisplay the
* screen, so we need not display anything yet.
* Indicate there is nothing yet on the screen.
*/
pos_clear();
}
}
}
/*
* Edit the next file in the command line list.
*/
public void
next_file(n)
int n;
{
if (curr_ac + n >= ac)
{
if (quit_at_eof)
quit();
error("No (N-th) next file");
} else
edit(av[curr_ac += n]);
}
/*
* Edit the previous file in the command line list.
*/
public void
prev_file(n)
int n;
{
if (curr_ac - n < 0)
error("No (N-th) previous file");
else
edit(av[curr_ac -= n]);
}
/*
* Copy a file directly to standard output.
* Used if standard output is not a tty.
*/
static void
cat_file()
{
register int c;
while ((c = ch_forw_get()) != EOF)
putc(c);
flush();
}
/*
* Entry point.
*/
main(argc, argv)
int argc;
char *argv[];
{
char *getenv();
/*
* Process command line arguments and LESS environment arguments.
* Command line arguments override environment arguments.
*/
init_option();
scan_option(getenv("LESS"));
argv++;
while ( (--argc > 0) &&
(argv[0][0] == '-' || argv[0][0] == '+') &&
argv[0][1] != '\0')
scan_option(*argv++);
#if EDITOR
editor = getenv("EDITOR");
if (editor == NULL || *editor == '\0')
editor = EDIT_PGM;
#endif
/*
* Set up list of files to be examined.
*/
ac = argc;
av = argv;
curr_ac = 0;
/*
* Set up terminal, etc.
*/
is_tty = isatty(1);
if (!is_tty)
{
/*
* Output is not a tty.
* Just copy the input file(s) to output.
*/
if (ac < 1)
{
edit("-");
cat_file();
} else
{
do
{
edit((char *)NULL);
if (file >= 0)
cat_file();
} while (++curr_ac < ac);
}
exit(0);
}
raw_mode(1);
get_term();
open_getc();
init();
if (back_scroll < 0)
{
/* {{ KLUDGE }} */
back_scroll = sc_height-1;
if (top_scroll)
back_scroll--;
}
if (setjmp(main_loop))
quit();
init_signals();
/*
* Select the first file to examine.
*/
if (ac < 1)
edit("-"); /* Standard input */
else
{
/*
* Try all the files named as command arguments.
* We are simply looking for one which can be
* opened without error.
*/
do
{
edit((char *)NULL);
if (file >= 0)
/* We can open this file. */
break;
putc('\n'); flush();
} while (++curr_ac < ac);
}
if (file >= 0)
commands();
quit();
}
/*
* Exit the program.
*/
public void
quit()
{
/*
* Put cursor at bottom left corner, clear the line,
* reset the terminal modes, and exit.
*/
lower_left();
clear_eol();
deinit();
flush();
raw_mode(0);
exit(0);
}
SHAR_EOF
echo shar: extracting option.c
cat - << \SHAR_EOF > option.c
/*
* Process command line options.
* Each option is a single letter which controls a program variable.
* The options have defaults which may be changed via
* the command line option, or toggled via the "-" command.
*/
#include "less.h"
#define toupper(c) ((c)-'a'+'A')
/*
* Types of options.
*/
#define BOOL 01 /* Boolean option: 0 or 1 */
#define TRIPLE 02 /* Triple-valued option: 0, 1 or 2 */
#define NUMBER 04 /* Numeric option */
#define NO_TOGGLE 0100 /* Option cannot be toggled with "-" cmd */
/*
* Variables controlled by command line options.
*/
public int p_nbufs, f_nbufs; /* Number of buffers. There are two values,
one used for input from a pipe and
the other for input from a file. */
public int clean_data; /* Can we assume the data is "clean"?
(That is, free of nulls, etc) */
public int quiet; /* Should we suppress the audible bell? */
public int top_search; /* Should forward searches start at the top
of the screen? (alternative is bottom) */
public int top_scroll; /* Repaint screen from top?
(alternative is scroll from bottom) */
public int pr_type; /* Type of prompt (short, medium, long) */
public int bs_mode; /* How to process backspaces */
public int know_dumb; /* Don't complain about dumb terminals */
public int quit_at_eof; /* Quit after hitting end of file twice */
public int squeeze; /* Squeeze multiple blank lines into one */
public int tabstop; /* Tab settings */
public int back_scroll; /* Repaint screen on backwards movement */
public int twiddle; /* Display "~" for lines after EOF */
extern int nbufs;
extern char *first_cmd;
extern char *every_first_cmd;
#define DEF_F_NBUFS 5 /* Default for f_nbufs */
#define DEF_P_NBUFS 12 /* Default for p_nbufs */
static struct option
{
char oletter; /* The controlling letter (a-z) */
char otype; /* Type of the option */
int odefault; /* Default value */
int *ovar; /* Pointer to the associated variable */
char *odesc[3]; /* Description of each value */
} option[] =
{
{ 'c', BOOL, 0, &clean_data,
{ "Don't assume data is clean",
"Assume data is clean",
NULL
}
},
{ 'd', BOOL|NO_TOGGLE, 0, &know_dumb,
{ NULL, NULL, NULL}
},
{ 'e', BOOL, 0, &quit_at_eof,
{ "Don't quit at end-of-file",
"Quit at end-of-file",
NULL
}
},
{ 'h', NUMBER, -1, &back_scroll,
{ "Backwards scroll limit is %d lines",
NULL, NULL
}
},
{ 'p', BOOL, 0, &top_scroll,
{ "Repaint by scrolling from bottom of screen",
"Repaint by painting from top of screen",
NULL
}
},
{ 'x', NUMBER, 8, &tabstop,
{ "Tab stops every %d spaces",
NULL, NULL
}
},
{ 's', BOOL, 0, &squeeze,
{ "Don't squeeze multiple blank lines",
"Squeeze multiple blank lines",
NULL
}
},
{ 't', BOOL, 1, &top_search,
{ "Forward search starts from bottom of screen",
"Forward search starts from top of screen",
NULL
}
},
{ 'w', BOOL, 1, &twiddle,
{ "Display nothing for lines after end-of-file",
"Display ~ for lines after end-of-file",
NULL
}
},
{ 'm', TRIPLE, 0, &pr_type,
{ "Prompt with a colon",
"Prompt with a message",
"Prompt with a verbose message"
}
},
{ 'q', TRIPLE, 0, &quiet,
{ "Ring the bell for errors AND at eof/bof",
"Ring the bell for errors but not at eof/bof",
"Never ring the bell"
}
},
{ 'u', TRIPLE, 0, &bs_mode,
{ "Underlined text displayed in underline mode",
"All backspaces cause overstrike",
"Backspaces print as ^H"
}
},
{ '\0' }
};
public char all_options[64]; /* List of all valid options */
/*
* Initialize each option to its default value.
*/
public void
init_option()
{
register struct option *o;
register char *p;
/*
* First do special cases, not in option table.
*/
first_cmd = every_first_cmd = NULL;
f_nbufs = DEF_F_NBUFS; /* -bf */
p_nbufs = DEF_P_NBUFS; /* -bp */
p = all_options;
*p++ = 'b';
for (o = option; o->oletter != '\0'; o++)
{
/*
* Set each variable to its default.
* Also make a list of all options, in "all_options".
*/
*(o->ovar) = o->odefault;
*p++ = o->oletter;
if (o->otype & TRIPLE)
*p++ = toupper(o->oletter);
}
*p = '\0';
}
/*
* Toggle command line flags from within the program.
* Used by the "-" command.
*/
public void
toggle_option(c)
int c;
{
register struct option *o;
char message[100];
char buf[5];
/*
* First check for special cases not handled by the option table.
*/
switch (c)
{
case 'b':
sprintf(message, "%d buffers", nbufs);
error(message);
return;
}
for (o = option; o->oletter != '\0'; o++)
{
if ((o->otype & BOOL) && (o->oletter == c) &&
(o->otype & NO_TOGGLE) == 0)
{
/*
* Boolean option:
* just toggle it.
*/
*(o->ovar) = ! *(o->ovar);
error(o->odesc[*(o->ovar)]);
return;
} else if ((o->otype & TRIPLE) && (o->oletter == c) &&
(o->otype & NO_TOGGLE) == 0)
{
/*
* Triple-valued option with lower case letter:
* make it 1 unless already 1, then make it 0.
*/
*(o->ovar) = (*(o->ovar) == 1) ? 0 : 1;
error(o->odesc[*(o->ovar)]);
return;
} else if ((o->otype & TRIPLE) && (toupper(o->oletter) == c) &&
(o->otype & NO_TOGGLE) == 0)
{
/*
* Triple-valued option with upper case letter:
* make it 2 unless already 2, then make it 0.
*/
*(o->ovar) = (*(o->ovar) == 2) ? 0 : 2;
error(o->odesc[*(o->ovar)]);
return;
} else if ((o->otype & NUMBER) && (o->oletter == c) &&
(o->otype & NO_TOGGLE) == 0)
{
sprintf(message, o->odesc[0], *(o->ovar));
error(message);
return;
}
}
if (control_char(c))
sprintf(buf, "^%c", carat_char(c));
else
sprintf(buf, "%c", c);
sprintf(message, "\"-%s\": no such flag. Use one of \"%s\"",
buf, all_options);
error(message);
}
/*
* Scan an argument (either from command line or from LESS environment
* variable) and process it.
*/
public void
scan_option(s)
char *s;
{
register struct option *o;
register int c;
if (s == NULL)
return;
next:
if (*s == '\0')
return;
switch (c = *s++)
{
case '-':
case ' ':
case '\t':
goto next;
case '+':
if (*s == '+')
every_first_cmd = ++s;
first_cmd = s;
return;
case 'b':
switch (*s)
{
case 'f':
s++;
f_nbufs = getnum(&s, 'b');
break;
case 'p':
s++;
p_nbufs = getnum(&s, 'b');
break;
default:
f_nbufs = p_nbufs = getnum(&s, 'b');
break;
}
goto next;
}
for (o = option; o->oletter != '\0'; o++)
{
if ((o->otype & BOOL) && (o->oletter == c))
{
*(o->ovar) = ! o->odefault;
goto next;
} else if ((o->otype & TRIPLE) && (o->oletter == c))
{
*(o->ovar) = (o->odefault == 1) ? 0 : 1;
goto next;
} else if ((o->otype & TRIPLE) && (toupper(o->oletter) == c))
{
*(o->ovar) = (o->odefault == 2) ? 0 : 2;
goto next;
} else if ((o->otype & NUMBER) && (o->oletter == c))
{
*(o->ovar) = getnum(&s, c);
goto next;
}
}
printf("\"-%c\": invalid flag\n", c);
exit(1);
}
/*
* Translate a string into a number.
* Like atoi(), but takes a pointer to a char *, and updates
* the char * to point after the translated number.
*/
static int
getnum(sp, c)
char **sp;
int c;
{
register char *s;
register int n;
s = *sp;
if (*s < '0' || *s > '9')
{
printf("number is required after -%c\n", c);
exit(1);
}
n = 0;
while (*s >= '0' && *s <= '9')
n = 10 * n + *s++ - '0';
*sp = s;
return (n);
}
SHAR_EOF
echo shar: extracting prim.c
cat - << \SHAR_EOF > prim.c
/*
* Primitives for displaying the file on the screen.
*/
#include "less.h"
#include "position.h"
public int hit_eof; /* Keeps track of how many times we hit end of file */
extern int quiet;
extern int top_search;
extern int top_scroll;
extern int back_scroll;
extern int sc_width, sc_height;
extern int sigs;
extern char *line;
extern char *first_cmd;
/*
* Sound the bell to indicate he is trying to move past end of file.
*/
static void
eof_bell()
{
if (quiet == NOT_QUIET)
bell();
else
vbell();
}
/*
* Check to see if the end of file is currently "displayed".
*/
static void
eof_check()
{
POSITION pos;
/*
* If the bottom line is empty, we are at EOF.
* If the bottom line ends at the file length,
* we must be just at EOF.
*/
pos = position(BOTTOM_PLUS_ONE);
if (pos == NULL_POSITION || pos == ch_length())
hit_eof++;
}
/*
* Display n lines, scrolling forward,
* starting at position pos in the input file.
* "force" means display the n lines even if we hit end of file.
* "only_last" means display only the last screenful if n > screen size.
*/
static void
forw(n, pos, force, only_last)
register int n;
POSITION pos;
int force;
int only_last;
{
int eof = 0;
int nlines = 0;
int repaint_flag;
/*
* repaint_flag tells us not to display anything till the end,
* then just repaint the entire screen.
*/
repaint_flag = (only_last && n > sc_height-1);
if (!repaint_flag)
{
if (top_scroll && n >= sc_height - 1)
{
/*
* Start a new screen.
* {{ This is not really desirable if we happen
* to hit eof in the middle of this screen,
* but we don't know if that will happen now. }}
*/
clear();
home();
force = 1;
} else
{
lower_left();
clear_eol();
}
if (pos != position(BOTTOM_PLUS_ONE))
{
/*
* This is not contiguous with what is
* currently displayed. Clear the screen image
* (position table) and start a new screen.
*/
pos_clear();
add_forw_pos(pos);
force = 1;
if (top_scroll)
{
clear();
home();
} else
{
puts("...skipping...\n");
}
}
}
while (--n >= 0)
{
/*
* Read the next line of input.
*/
pos = forw_line(pos);
if (pos == NULL_POSITION)
{
/*
* End of file: stop here unless the top line
* is still empty, or "force" is true.
*/
eof = 1;
if (!force && position(TOP) != NULL_POSITION)
break;
line = NULL;
}
/*
* Add the position of the next line to the position table.
* Display the current line on the screen.
*/
add_forw_pos(pos);
nlines++;
if (!repaint_flag)
put_line();
}
if (eof)
hit_eof++;
else
eof_check();
if (nlines == 0)
eof_bell();
else if (repaint_flag)
repaint();
}
/*
* Display n lines, scrolling backward.
*/
static void
back(n, pos, force, only_last)
register int n;
POSITION pos;
int force;
int only_last;
{
int nlines = 0;
int repaint_flag;
repaint_flag = (n > back_scroll || (only_last && n > sc_height-1));
hit_eof = 0;
while (--n >= 0)
{
/*
* Get the previous line of input.
*/
pos = back_line(pos);
if (pos == NULL_POSITION)
{
/*
* Beginning of file: stop here unless "force" is true.
*/
if (!force)
break;
line = NULL;
}
/*
* Add the position of the previous line to the position table.
* Display the line on the screen.
*/
add_back_pos(pos);
nlines++;
if (!repaint_flag)
{
home();
add_line();
put_line();
}
}
eof_check();
if (nlines == 0)
eof_bell();
else if (repaint_flag)
repaint();
}
/*
* Display n more lines, forward.
* Start just after the line currently displayed at the bottom of the screen.
*/
public void
forward(n, only_last)
int n;
int only_last;
{
POSITION pos;
pos = position(BOTTOM_PLUS_ONE);
if (pos == NULL_POSITION)
{
eof_bell();
hit_eof++;
return;
}
forw(n, pos, 0, only_last);
}
/*
* Display n more lines, backward.
* Start just before the line currently displayed at the top of the screen.
*/
public void
backward(n, only_last)
int n;
int only_last;
{
POSITION pos;
pos = position(TOP);
if (pos == NULL_POSITION)
{
/*
* This will almost never happen,
* because the top line is almost never empty.
*/
eof_bell();
return;
}
back(n, pos, 0, only_last);
}
/*
* Repaint the screen, starting from a specified position.
*/
static void
prepaint(pos)
POSITION pos;
{
hit_eof = 0;
forw(sc_height-1, pos, 0, 0);
}
/*
* Repaint the screen.
*/
public void
repaint()
{
/*
* Start at the line currently at the top of the screen
* and redisplay the screen.
*/
prepaint(position(TOP));
}
/*
* Jump to the end of the file.
* It is more convenient to paint the screen backward,
* from the end of the file toward the beginning.
*/
public void
jump_forw()
{
POSITION pos;
if (ch_end_seek())
{
error("Cannot seek to end of file");
return;
}
pos = ch_tell();
clear();
pos_clear();
add_back_pos(pos);
back(sc_height - 1, pos, 0, 0);
}
/*
* Jump to line n in the file.
*/
public void
jump_back(n)
register int n;
{
register int c;
/*
* This is done the slow way, by starting at the beginning
* of the file and counting newlines.
*/
if (ch_seek((POSITION)0))
{
/*
* Probably a pipe with beginning of file no longer buffered.
*/
error("Cannot get to beginning of file");
return;
}
/*
* Start counting lines.
*/
while (--n > 0)
{
while ((c = ch_forw_get()) != '\n')
if (c == EOF)
{
error("File is not that long");
/* {{ Maybe tell him how long it is? }} */
return;
}
}
/*
* Finally found the place to start.
* Clear and redisplay the screen from there.
*
* {{ We *could* figure out if the new position is
* close enough to just scroll there without clearing
* the screen, but it's not worth it. }}
*/
prepaint(ch_tell());
}
/*
* Jump to a specified percentage into the file.
* This is a poor compensation for not being able to
* quickly jump to a specific line number.
*/
public void
jump_percent(percent)
int percent;
{
POSITION pos, len;
/*
* Determine the position in the file
* (the specified percentage of the file's length).
*/
if ((len = ch_length()) == NULL_POSITION)
{
error("Don't know length of file");
return;
}
pos = (percent * len) / 100;
jump_loc(pos);
}
public void
jump_loc(pos)
POSITION pos;
{
register int c;
register int nline;
POSITION tpos;
/*
* See if the desired line is BEFORE the currently
* displayed screen. If so, see if it is close enough
* to scroll backwards to it.
*/
tpos = position(TOP);
if (pos < tpos)
{
for (nline = 1; nline <= back_scroll; nline++)
{
tpos = back_line(tpos);
if (tpos == NULL_POSITION || tpos <= pos)
{
back(nline, position(TOP), 1, 0);
return;
}
}
} else if ((nline = onscreen(pos)) >= 0)
{
/*
* The line is currently displayed.
* Just scroll there.
*/
forw(nline, position(BOTTOM_PLUS_ONE), 1, 0);
return;
}
/*
* Line is not on screen.
* Back up to the beginning of the current line.
*/
if (ch_seek(pos))
{
error("Cannot seek to that position");
return;
}
while ((c = ch_back_get()) != '\n' && c != EOF)
;
if (c == '\n')
(void) ch_forw_get();
/*
* Clear and paint the screen.
*/
prepaint(ch_tell());
}
/*
* The table of marks.
* A mark is simply a position in the file.
*/
static POSITION marks[26];
/*
* Initialize the mark table to show no marks are set.
*/
public void
init_mark()
{
int i;
for (i = 0; i < 26; i++)
marks[i] = NULL_POSITION;
}
/*
* See if a mark letter is valid (between a and z).
*/
static int
badmark(c)
int c;
{
if (c < 'a' || c > 'z')
{
error("Choose a letter between 'a' and 'z'");
return (1);
}
return (0);
}
/*
* Set a mark.
*/
public void
setmark(c)
int c;
{
if (badmark(c))
return;
marks[c-'a'] = position(TOP);
}
/*
* Go to a previously set mark.
*/
public void
gomark(c)
int c;
{
POSITION pos;
if (badmark(c))
return;
if ((pos = marks[c-'a']) == NULL_POSITION)
error("mark not set");
else
jump_loc(pos);
}
/*
* Search for the n-th occurence of a specified pattern,
* either forward (direction == '/'), or backwards (direction == '?').
*/
public void
search(direction, pattern, n)
int direction;
char *pattern;
register int n;
{
register int search_forward = (direction == '/');
POSITION pos, linepos;
#if RECOMP
char *re_comp();
char *errmsg;
/*
* (re_comp handles a null pattern internally,
* so there is no need to check for a null pattern here.)
*/
if ((errmsg = re_comp(pattern)) != NULL)
{
error(errmsg);
return;
}
#else
#if REGCMP
char *regcmp();
static char *cpattern = NULL;
if (pattern == NULL || *pattern == '\0')
{
/*
* A null pattern means use the previous pattern.
* The compiled previous pattern is in cpattern, so just use it.
*/
if (cpattern == NULL)
{
error("No previous regular expression");
return;
}
} else
{
/*
* Otherwise compile the given pattern.
*/
char *s;
if ((s = regcmp(pattern, 0)) == NULL)
{
error("Invalid pattern");
return;
}
if (cpattern != NULL)
free(cpattern);
cpattern = s;
}
#else
static char lpbuf[100];
static char *last_pattern = NULL;
if (pattern == NULL || *pattern == '\0')
{
/*
* Null pattern means use the previous pattern.
*/
if (last_pattern == NULL)
{
error("No previous regular expression");
return;
}
pattern = last_pattern;
} else
{
strcpy(lpbuf, pattern);
last_pattern = lpbuf;
}
#endif
#endif
/*
* Figure out where to start the search.
*/
if (position(TOP) == NULL_POSITION)
{
/*
* Nothing is currently displayed.
* Start at the beginning of the file.
* (This case is mainly for first_cmd searches,
* for example, "+/xyz" on the command line.)
*/
pos = (POSITION)0;
} else if (!search_forward)
{
/*
* Backward search: start just before the top line
* displayed on the screen.
*/
pos = position(TOP);
} else if (top_search)
{
/*
* Forward search and "start from top".
* Start at the second line displayed on the screen.
*/
pos = position(TOP_PLUS_ONE);
} else
{
/*
* Forward search but don't "start from top".
* Start just after the bottom line displayed on the screen.
*/
pos = position(BOTTOM_PLUS_ONE);
}
if (pos == NULL_POSITION)
{
/*
* Can't find anyplace to start searching from.
*/
error("Nothing to search");
return;
}
for (;;)
{
/*
* Get lines until we find a matching one or
* until we hit end-of-file (or beginning-of-file
* if we're going backwards).
*/
if (sigs)
/*
* A signal aborts the search.
*/
return;
if (search_forward)
{
/*
* Read the next line, and save the
* starting position of that line in linepos.
*/
linepos = pos;
pos = forw_raw_line(pos);
} else
{
/*
* Read the previous line and save the
* starting position of that line in linepos.
*/
pos = back_raw_line(pos);
linepos = pos;
}
if (pos == NULL_POSITION)
{
/*
* We hit EOF/BOF without a match.
*/
error("Pattern not found");
return;
}
/*
* Test the next line to see if we have a match.
* This is done in a variety of ways, depending
* on what pattern matching functions are available.
*/
#if REGCMP
if ( (regex(cpattern, line) != NULL)
#else
#if RECOMP
if ( (re_exec(line) == 1)
#else
if ( (match(pattern, line))
#endif
#endif
&& (--n <= 0) )
/*
* Found the matching line.
*/
break;
}
jump_loc(linepos);
}
#if (!REGCMP) && (!RECOMP)
/*
* We have neither regcmp() nor re_comp().
* We use this function to do simple pattern matching.
* It supports no metacharacters like *, etc.
*/
static int
match(pattern, buf)
char *pattern, *buf;
{
register char *pp, *lp;
for ( ; *buf != '\0'; buf++)
{
for (pp = pattern, lp = buf; *pp == *lp; pp++, lp++)
if (*pp == '\0' || *lp == '\0')
break;
if (*pp == '\0')
return (1);
}
return (0);
}
#endif
SHAR_EOF
More information about the Mod.sources
mailing list