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What does "$$" mean in the shell?
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What does !$ mean?
120372
How to typeset $:=$ correctly?
76281
What does $(command) & do?
54322
What is the difference between the "...", '...', $'...', and $"..." quotes in the shell?
31017
What are the numbers in var_dump result?
15213
How to echo an echo in php?
148277
! Missing $ inserted.  $
106734
Redirecting output to a variable?
95209
php : Capturing the command output
64218
Storing output of command in shell variable
86824
Problem with Bash output redirection
98451
Why can't I echo the characters #! in a string in bash?
750
Need help to interpret output of free command
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Why doesn't echo called as /bin/sh -c echo foo output anything?
31627
How to print only defined variables (shell and/or environment variables) in bash
102224
Does variable=$(...) store the command or the result of the command in POSIX sh