32 lines
827 B
Bash
32 lines
827 B
Bash
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#!/bin/sh
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# Reads filenames on stdin, xz-compresses each in place.
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# Not optimal for "compress relatively few, large files" scenario!
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# How many xz's to run in parallel:
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procgroup=""
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while test "$#" != 0; do
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# Get it from -jNUM
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N="${1#-j}"
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if test "$N" = "$1"; then
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# Not -j<something> - warn and ignore
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echo "parallel_xz: warning: unrecognized argument: '$1'"
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else
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procgroup="$N"
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fi
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shift
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done
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#This seems to cause problems with large numbers
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if (( $procgroup > 6 )); then
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procgroup=6
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fi
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# If told to use only one cpu:
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test "$procgroup" || exec xargs -r xz
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test "$procgroup" = 1 && exec xargs -r xz
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# xz has some startup cost. If files are really small,
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# this cost might be significant. To combat this,
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# process several files (in sequence) by each xz process via -n 16:
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exec xargs -r -n 16 -P $procgroup xz
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