mirror of https://github.com/tLDP/LDP
35 lines
866 B
Bash
35 lines
866 B
Bash
#!/bin/bash
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if [ -z "$1" ]
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then
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Filename=names.data # Default, if no filename specified.
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else
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Filename=$1
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fi
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#+ Filename=${1:-names.data}
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# can replace the above test (parameter substitution).
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count=0
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echo
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while [ "$name" != Smith ] # Why is variable $name in quotes?
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do
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read name # Reads from $Filename, rather than stdin.
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echo $name
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let "count += 1"
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done <"$Filename" # Redirects stdin to file $Filename.
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# ^^^^^^^^^^^^
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echo; echo "$count names read"; echo
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# Note that in some older shell scripting languages,
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#+ the redirected loop would run as a subshell.
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# Therefore, $count would return 0, the initialized value outside the loop.
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# Bash and ksh avoid starting a subshell whenever possible,
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# +so that this script, for example, runs correctly.
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#
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# Thanks to Heiner Steven for pointing this out.
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exit 0
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