26 lines
498 B
Bash
Executable File
26 lines
498 B
Bash
Executable File
#!/bin/sh
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# usage: ifchange target temporary
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unset timestamp
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if [ "$1" = --timestamp ]; then
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timestamp=yes
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shift
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fi
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target="$1"
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temp="$2"
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if [ "$temp" = - ]; then
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temp="tmpdata$$.tmp~"
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cat > "$temp" || exit $?
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trap 'rm -f "$temp"' 0
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fi
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if cmp "$target" "$temp" >/dev/null 2>&1; then
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echo "$target unchanged"
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rm -f "$temp"
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else
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echo "$target updated"
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mv -f "$temp" "$target"
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fi
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if [ $timestamp ]; then
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touch `dirname "$target"`/.time.`basename "$target"`
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fi
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