However in Bash, introducing a pipe means the individual commands are run in subshells. Consider this: ... The output of the 2nd echo command prints just a single space. Whaaaa? What happened to my …

Sep 14, 2012 · In Bash, there appear to be several variables which hold special, consistently-meaning values. For instance, ./myprogram &; echo $! will return the PID of the process which …

Sep 27, 2015 · Here-strings in bash are implemented via temporary files, usually in the format /tmp/sh-thd.<random string>, which are later unlinked, thus making them occupy some memory space …

Sep 3, 2017 · For understanding bash code it is usually very helpful to set the -x option: set -x # within a script / function or when calling a script: bash -vx ./script.sh With loops this is a little less helpful. But …

Modern shells such as Bash and Zsh have inherited this construct from Ksh, but it is not part of the POSIX specification. If you're in an environment where you have to be strictly POSIX compliant, stay …

One way to begin debugging your bash script would be to start a subshell with the -x option: ... This will show you every command, and its arguments, which is executed when starting that shell.

Oct 18, 2013 · What is the operator =~ called? I'm not sure it has a name. The bash documentation just calls it the =~ operator. Is it only used to compare the right side against the left side? The right side is …

bash shell scripting control-flow Improve this question edited Nov 16, 2011 at 22:16 Gilles 'SO- stop being evil'

Jul 25, 2017 · Furthermore, when you use bash -c, behavior is different than if you run an executable shell script, because in the latter case the argument with index 0 is the shell command used to invoke it.

The reason is that Bash is untyped. The -eq causes the strings to be interpreted as integers if possible including base conversion: ... And 0 if Bash thinks it is just a string: ... So [[ "yes" -eq "no" ]] is …