why echo printing the files names ?
sinks_index=`pacmd list-sinks | grep "index:"` for i in $sinks_index do echo $i done
gives this output
audio_name_switcher.sh audio.py audio.sh switch_audio.sh index: 1 index: 2 index: 3
but running pacmd list-sinks | grep "index:"
in the shell gives * index: 1 index: 2 index: 3
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Answer
pacmd
returns *
pattern.
In for ... in ...; do ... done
loop, the list pattern contains *
without any protection.
So, bash replace *
by all files found in current directory.
It’s the glob functionality.
You could temporary deactivate glob with GLOBIGNORE
variable (see man bash
):
#! /bin/bash sinks_index='* index: 1 index: 2 index: 3' GLOBIGNORE="*" echo "With GLOBIGNORE" for i in $sinks_index do echo "UNSET GLOB: " $i unset GLOBIGNORE echo " SET GLOB: " $i echo " SET GLOB: $i" done unset GLOBIGNORE
Reactivate global in and after loop.
- In: it may be necessary for other stuff;
- After: if your list is empty, the execution do not enter in the loop.
Note about $i
and "$i"
after reactivate glob in the loop:
- The protection with
"..."
stop glob for bash echo command but do not stop${...}
interpretation.