34 lines
723 B
Bash
34 lines
723 B
Bash
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# simplest case
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cat <(echo "hello 1")
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# can have more than one
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cat <(echo "hello 2") <(echo "hello 3")
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# doesn't work in quotes
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echo "<(echo \"hello 0\")"
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# process substitution can be nested inside command substitution
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echo $(cat <(echo "hello 4"))
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# example from http://wiki.bash-hackers.org/syntax/expansion/proc_subst
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# process substitutions can be passed to a function as parameters or
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# variables
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f() {
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cat "$1" >"$x"
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}
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x=>(tr '[:lower:]' '[:upper:]') f <(echo 'hi there')
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# process substitution can be combined with redirection on exec
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rm -f err
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# save stderr
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exec 4>&2
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# copy stderr to a file
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exec 2> >(tee err)
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echo "hello error" >&2
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sync
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# restore stderr
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exec 2>&4
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cat err
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rm -f err
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echo "hello stderr" >&2
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