Interesting Bourne shell usage, and ^ for pipe
59577
wcs at ho95b.UUCP
Fri May 25 03:40:01 AEST 1984
Dave Sherman posted a quick shell program, containing:
$ for i in *.c
> do
......
> done ^ tee junk
What interested me about this was the use of the ^caret
as a pipe symbol, instead of the | vertical bar. This is kind
of an archaism; the Korn Shell (ksh) has dropped it, although
the System V shell still supports it. Do many people out there
use ^ ? I much prefer the ability to say
grep ^joeuser /etc/passwd
without being told
sh: joeuser: not found
Another note on this is that /bin/sh forks off a process to do
the for loop when directing its output to a pipe; ksh doesn't.
This feature, and builtins for echo and expr considerably speed
up shell script execution in ksh.
Bill
--
The virtual keyboard of:
Bill Stewart
AT&T Bell Labs, Holmdel NJ
...!ihnp4!ho95b!wcs
More information about the Comp.unix
mailing list