mirror of https://github.com/tLDP/LDP
56 lines
1.3 KiB
Bash
56 lines
1.3 KiB
Bash
#!/bin/bash
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# letter-count.sh: Counting letter occurrences in a text file.
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# Written by Stefano Palmeri.
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# Used in ABS Guide with permission.
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# Slightly modified by document author.
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MINARGS=2 # Script requires at least two arguments.
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E_BADARGS=65
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FILE=$1
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let LETTERS=$#-1 # How many letters specified (as command-line args).
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# (Subtract 1 from number of command-line args.)
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show_help(){
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echo
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echo Usage: `basename $0` file letters
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echo Note: `basename $0` arguments are case sensitive.
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echo Example: `basename $0` foobar.txt G n U L i N U x.
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echo
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}
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# Checks number of arguments.
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if [ $# -lt $MINARGS ]; then
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echo
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echo "Not enough arguments."
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echo
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show_help
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exit $E_BADARGS
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fi
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# Checks if file exists.
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if [ ! -f $FILE ]; then
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echo "File \"$FILE\" does not exist."
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exit $E_BADARGS
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fi
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# Counts letter occurrences .
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for n in `seq $LETTERS`; do
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shift
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if [[ `echo -n "$1" | wc -c` -eq 1 ]]; then # Checks arg.
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echo "$1" -\> `cat $FILE | tr -cd "$1" | wc -c` # Counting.
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else
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echo "$1 is not a single char."
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fi
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done
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exit $?
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# This script has exactly the same functionality as letter-count2.sh,
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#+ but executes faster.
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# Why?
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