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7259
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aaronmk
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#!/bin/sh
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# Wraps lockfile/dotlockfile
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7260
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aaronmk
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# Usage: env [interval=...] self lockfile
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7259
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aaronmk
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7426
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aaronmk
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selfDir="$(dirname -- "$0")"
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7262
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aaronmk
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: "${interval=5}" # s
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7260
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aaronmk
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7429
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aaronmk
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if test -n "$inner"; then
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"$selfDir/dotlockfile" -l -r 65535 -p "$lockfile" || exit
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echo "$pid" >"$lockfile" # use the outer process's PPID
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exit
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fi
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statFmtFlag="$(test "$(uname)" = Darwin && echo f || echo c)"
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7260
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aaronmk
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if test "$(uname)" = Darwin; then
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7429
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aaronmk
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file_group () { stat -f %Sg "$@"; }
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else
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file_group () { stat -c %G "$@"; }
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fi
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export lockfile="$1"
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if test "$(uname)" = Darwin; then
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7260
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aaronmk
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while ! shlock -p "$PPID" -f "$1"; do sleep "$interval"; done
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else
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7430
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aaronmk
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# Need to change primary group of the dotlockfile process to the group of
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# the dir to contain the lockfile, because dotlockfile otherwise reports a
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# "permission denied" error (even though the directory is actually writable,
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# dotlockfile thinks it isn't).
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# newgrp, the command that does this, does not pass arguments to the new
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# process, so they must instead be passed via environment variables and a
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# recursive invocation of lockfile (with the $inner recursion flag set).
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# Additionally, exec cannot be used to propagate the PPID (needed by
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# dotlockfile) because newgrp creates a new process rather than using exec,
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# so it must be manually entered into the lockfile after dotlockfile runs.
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7429
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aaronmk
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export SHELL="$0" inner=1 pid="$PPID"
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newgrp "$(file_group "$(dirname -- "$lockfile")")"
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7260
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aaronmk
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fi
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