2015-03-07 18:01:18 -0600, Eduardo A. Bustamante López: > > But I am wondering if there is a walkaround to deal with errors in > > <(). The ideal behavior should be that if there is a error in <(), > > then we should not consider commandA is executed correctly even if its > > return status is 0. > Again, address your questions to help-bash. [...]
Are bash questions no longer on topic here? bash-bug used to be the place to discuss bash (before help-bash was created). It maps to the gnu.bash.bug newsgroup. I don't think help-bash maps to usenet (though you can access it over NNTP on gmane). There's a alt.comp.lang.shell.unix.bourne-bash but it doesn't look very lively. What's the official line? To get back on a bug topic though: $ bash --norc bash-4.3$ echo <(exit 123) /dev/fd/63 bash-4.3$ echo "$!" 12142 bash-4.3$ wait "$!" bash: wait: pid 12142 is not a child of this shell Having the process substitution pid in $! is not very useful if you can't wait for it to retrieve the status. That also means it overrides the $! of a previous asynchronous job. That doesn't work well if there are more than one process substitutions as in diff <(cmd1) <(cmd2) (you get the pid of cmd2 in $1 (well the shell process waiting for cmd2)) That error message is also lying: ~$ bash --norc bash-4.3$ : <(sleep 100) bash-4.3$ wait $! bash: wait: pid 12291 is not a child of this shell bash-4.3$ ps -H PID TTY TIME CMD 4942 pts/9 00:00:00 zsh 12244 pts/9 00:00:00 bash 12291 pts/9 00:00:00 bash 12292 pts/9 00:00:00 sleep 12293 pts/9 00:00:00 ps clearly 12291 still is a child of this shell. (BTW, why not execute sleep in the same process like in command substitution?) -- Stephane
