Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-unknown-linux-gnu'
-DCONF_VENDOR='unknown' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H -I. -I. -I./include -I./lib -march=x86-64
-mtune=generic -O2 -pipe -fstack-protector --param=ssp-buffer-size=4
-D_FORTIFY_SOURCE=2
-DDEFAULT_PATH_VALUE='/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin'
-DSTANDARD_UTILS_PATH='/usr/bin:/bin:/usr/sbin:/sbin'
-DSYS_BASHRC='/etc/bash.bashrc' -DSYS_BASH_LOGOUT='/etc/bash.bash_logout'
uname output: Linux medinvdj 3.6.9-1-ARCH #1 SMP PREEMPT Tue Dec 4 08:04:10
CET 2012 x86_64 GNU/Linux
Machine Type: x86_64-unknown-linux-gnu
Bash Version: 4.2
Patch Level: 39
Release Status: release
I've noticed several issues with coproc, as stated below.
1)
First of all, the man page and help output state:
`The return status of a coprocess is the exit status of command.'
No matter what, coproc seems to always return true.
To reproduce:
coproc false || echo error1 >&2; wait "$COPROC_PID" || echo error2 >&2
Output:
[1] 31769
[1]+ Exit 1 coproc COPROC false
error2
2)
However, the exception to #1 is my second issue, with is that coproc
always
seems to fail when called within the test portion of an if statement. I
have
absolutely no idea why this happens.
To reproduce:
if ! coproc false; then echo error1 >&2; fi; wait "$COPROC_PID" || echo
error2 >&2
Output:
[1] 3971
error1
[1]+ Exit 1 ! coproc COPROC false
error2
3)
The first two issues aren't THAT big of a deal, because you can simply not
worry about coproc's exit status and use wait's. That leads me to the
third
and largest issue, which is that "NAME_PID" only appears to work properly
either when in an interactive shell or when there's no command between the
coproc and the wait.
To reproduce:
#!/bin/bash
# this one works
coproc mycoproc { false ; }
if ! wait "$mycoproc_PID"; then
echo "error1" >&2
fi
# this one does not
coproc mycoproc { false; }
while read -ru "${mycoproc[0]}" line; do
echo "coproc: $line"
done
if ! wait "$mycoproc_PID"; then
echo "error2" >&2
fi
Output:
error1
script: line 14: wait: `': not a pid or valid job spec
error2
The whole reason I'm using a coprocess instead of process substitution is
to be
able to read the output into an array while also checking the exit status.
For
the time being, I can use a named pipe, but I was rather excited about being
able to do this without having to worry about cleaning up files.
Thanks for your time, I know this was a long one.
-DJ
