v07i121: Some simple but useful shell script tools

[Brandon S. Allbery - comp.sources.misc]

Posting-number: Volume 7, Issue 121
Submitted-by: frew%crseo at hub.ucsb.edu
Archive-name: sherror

Here are a couple of tools I use a LOT for writing shell scripts that
will be around for a while.  These tools let shell scripts generate
standard usage and error messages just like real programs (should).
A sample "production" script is included that demonstrates their usage.

#! /bin/sh
# This is a shell archive, meaning:
# 1. Remove everything above the #! /bin/sh line.
# 2. Save the resulting text in a file.
# 3. Execute the file with /bin/sh (not csh) to create the files:
#	README
#	sherror
#	usage
#	xch
# This archive created: Sun Aug  6 14:29:31 1989
# By:	Jim Frew ()
export PATH; PATH=/bin:$PATH
echo shar: extracting "'README'" '(615 characters)'
if test -f 'README'
then
	echo shar: will not over-write existing file "'README'"
else
sed 's/^X//' << \SHAR_EOF > 'README'
X06-Aug-1989
X
XHere are a couple of trivial utilities that make writing shell scripts
Xa lot easier.
X
X"usage" writes a usage message to the standard error output.
X
X"sherror" writes an error message to the standard error output.  If you
Xmake a link to sherror named "shbug", then the message says "BUG"
Xinstead of "ERROR".
X
XA simple script "xch" is included that demonstrates both usage and
Xsherror.
X
X#-----------------+-----------------------+-----------------------------
X# James Frew      | frew at crseo.ucsb.edu   | Computer Systems Lab., UCSB
X# +1 805 961 8413 | frew at ucsbuxa (BITNET) | Santa Barbara, CA 93106, USA
SHAR_EOF
if test 615 -ne "`wc -c < 'README'`"
then
	echo shar: error transmitting "'README'" '(should have been 615 characters)'
fi
fi # end of overwriting check
echo shar: extracting "'sherror'" '(659 characters)'
if test -f 'sherror'
then
	echo shar: will not over-write existing file "'sherror'"
else
sed 's/^X//' << \SHAR_EOF > 'sherror'
X#!/bin/sh
X
X# sh{error,bug} -- print shell script {error,bug} message
X
Xexec 1>&2
X
Xcase $0 in
X*bug)	severity=BUG
X	;;
X*)	severity=ERROR
X	;;
Xesac
X
Xpgm=`basename ${1:-command?}`
Xmsg="${2:-message?}"
Xfile=${3:-file?}
X
Xcase $# in
X3)	if [ -d "$file" ]; then
X		type=Directory
X	else
X		type=File
X	fi
X	echo "
X$pgm: $severity:
X	$type "\"$file\"": $msg
X"
X	;;
X*)	echo "
X$pgm: $severity:
X	$msg
X"
X	;;
Xesac
X
Xexit 1
X
X# 06-Aug-1989: placed in the public domain
X#-----------------+-----------------------+-----------------------------
X# James Frew      | frew at crseo.ucsb.edu   | Computer Systems Lab., UCSB
X# +1 805 961 8413 | frew at ucsbuxa (BITNET) | Santa Barbara, CA 93106, USA
SHAR_EOF
if test 659 -ne "`wc -c < 'sherror'`"
then
	echo shar: error transmitting "'sherror'" '(should have been 659 characters)'
fi
chmod +x 'sherror'
fi # end of overwriting check
echo shar: extracting "'usage'" '(515 characters)'
if test -f 'usage'
then
	echo shar: will not over-write existing file "'usage'"
else
sed 's/^X//' << \SHAR_EOF > 'usage'
X#!/bin/sh
X
X# usage -- standard usage message for shell scripts
X
Xexec 1>&2
X
Xpgm=`basename ${1:-command?}`
Xargs="${2-args?}"			# note "-" not ":-", in case no args
Xdescription="${3:-description?}"
X
Xecho "
X$pgm -- $description
X
XUsage: $pgm $args
X"
X
Xexit 1
X
X# 06-Aug-1989: placed in the public domain
X#-----------------+-----------------------+-----------------------------
X# James Frew      | frew at crseo.ucsb.edu   | Computer Systems Lab., UCSB
X# +1 805 961 8413 | frew at ucsbuxa (BITNET) | Santa Barbara, CA 93106, USA
SHAR_EOF
if test 515 -ne "`wc -c < 'usage'`"
then
	echo shar: error transmitting "'usage'" '(should have been 515 characters)'
fi
chmod +x 'usage'
fi # end of overwriting check
echo shar: extracting "'xch'" '(802 characters)'
if test -f 'xch'
then
	echo shar: will not over-write existing file "'xch'"
else
sed 's/^X//' << \SHAR_EOF > 'xch'
X#!/bin/sh
X
X[ $# = 2 ] || exec usage $0 'name1 name2' 'exchange files or directories'
X
Xfor check do
X	[ -d $check -o -f $check ] ||
X		exec sherror $0 'No such file or directory' $check
X	checkdir=`dirname $check`
X	[ -w $checkdir ] || exec sherror $0 'No write permission' $checkdir
Xdone
X
Xtmp=,`basename $0`$$
X[ -d $tmp -o -f $tmp ] && exec sherror $0 'temporary name already exists' $tmp
X[ -w . ] || exec sherror $0 'No write permission (for temporary name)' .
X
Xset -x
X
Xmv $1 $tmp	|| exit 1
Xmv $2 $1	|| exit 1
Xmv $tmp $2	|| exit 1
X
Xrm -f $tmp
X
X# 06-Aug-1989: placed in the public domain
X#-----------------+-----------------------+-----------------------------
X# James Frew      | frew at crseo.ucsb.edu   | Computer Systems Lab., UCSB
X# +1 805 961 8413 | frew at ucsbuxa (BITNET) | Santa Barbara, CA 93106, USA
SHAR_EOF
if test 802 -ne "`wc -c < 'xch'`"
then
	echo shar: error transmitting "'xch'" '(should have been 802 characters)'
fi
chmod +x 'xch'
fi # end of overwriting check
#	End of shell archive
exit 0
#-----------------+-----------------------+-----------------------------
# James Frew      | frew at crseo.ucsb.edu   | Computer Systems Lab., UCSB
# +1 805 961 8413 | frew at ucsbuxa (BITNET) | Santa Barbara, CA 93106, USA