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 …

Oct 27, 2021 · 24 strings commands together. Successive commands only execute if preceding ones succeed. Similarly, will allow the successive command to execute if the preceding fails. See Bash …

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.

530 = and == are for string comparisons -eq is for numeric comparisons -eq is in the same family as -lt, -le, -gt, -ge, and -ne == is specific to bash (not present in sh (Bourne shell), ...). Using POSIX = is …

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 considered …

Boolean evaluation in bash is actually used mainly for controlling the conditional evaluation of the operands, not their order. Typical usage is do_foo || do_bar_if_foo_fails or do_foo && …

Take a look at the Bash man page. This notation is part of what's called a here documents & here strings. It allows you the ability to generate multi-line data input as one continuous string. The …

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 …

What does echo $? mean in shell programming?true echo $? # echoes 0 false echo $? # echoes 1 From the manual: (acessible by calling man bash in your shell) ? Expands to the exit status of the most …

Apr 3, 2012 · What does a dollar sign followed by an at-sign (@) mean in a shell script? For example: umbrella_corp_options $@