How can I read variable text files through cat command?

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03-29-2012

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How can I read variable text files through cat command?

Hi.
I'm just wondering how can I read variable text files through cat command.
I made a shell script to count frequency of words and array them with variable conditions. It's only working for one file that I wrote in script now. But I want to make it working for every text file when I execute script in the terminal like this : './*.sh -a filename.txt' , './*.sh -a filename2.txt', './*.sh -a filename3.txt'

Here is the code. Give me some advices plz. Thanks

Code:

#!/bin/bash

ALPHABETICALLY=0
FREQUENTLY=0
DESCENDING=0
while [ $# -gt 0 ] ; do
        case $1 in
                "-h"|"--help")
                        echo "Usage $0 [-a|-n] [-r] <file-name>" >&2
                        exit 0
                        ;;
                "-a")
                ALPHABETICALLY=1        #-a specified, change the var
                cat test.txt|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort|uniq -c

                shift                   #shift cmdline arguments to the left
                        ;;
                "-ar")
                ALPHABETICALLY=1
                DESCENDING=1
               cat test.txt|cat test.txt|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort -r|uniq -c
                shift
                    ;;
                "-n")
                FREQUENTLY=1
                echo "$input"|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort -n|uniq -c|sort -n
                shift
                     ;;
                "-nr")
                FREQUENTLY=1
                DESCENDING=1
                cat test.txt|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort -n|uniq -c|sort -nr
                shift
                ;;
        esac
done

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03-29-2012

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You need to switch to using getopts in order to process all those command line arguments...this will give you the ability to specify the filename as a variable argument...

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getopts won't let him use long arguments like --help, though

I think this can be fixed simply enough, anyway. Ditch the argument with shift first, then use "$@" to get all remaining options.

Code:

#!/bin/bash

ALPHABETICALLY=0
FREQUENTLY=0
DESCENDING=0
while [ $# -gt 0 ] ; do
        case $1 in
                "-h"|"--help")
                        echo "Usage $0 [-a|-n] [-r] <file-name>" >&2
                        exit 0
                        ;;
                "-a")
                ALPHABETICALLY=1        #-a specified, change the var
                shift # Shift first, to ditch -a
                cat "$@" |tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort|uniq -c
                        ;;
                "-ar")
                shift # Shift first, to ditch -ar
                ALPHABETICALLY=1
                DESCENDING=1
               cat "$@"|cat test.txt|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort -r|uniq -c
                    ;;
                "-n")
                FREQUENTLY=1
                shift # Shift first, to ditch -n
                echo "$input"|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort -n|uniq -c|sort -n
                     ;;
                "-nr")
                FREQUENTLY=1
                DESCENDING=1
                shift # Shift first, to ditch -nr
                cat "$@"|tr -d '[:punct:]'|sed 's/ /\
/g'|tr -s '\n'|tr '[A-Z]' '[a-z]'|sort -n|uniq -c|sort -nr
                shift
                ;;
        esac
done

I'd have built the program a little differently though, putting the actual operations outside the loop, but it looks like you're planning on doing that anyway. You don't have to test for every combination of -a, -ar, -n, -nr though, you can process the 'a', 'r', 'n' individually:

Code:

while [ "$#" -gt 0 ]
do
        case "$1" in
        --help) # long argument
                echo "stuff" >&2
                exit 0
                ;;

        --*)
                echo "Unknown long argument $1" >&2
                exit 1
                ;;

        -[^-]*) # Short arguments
                for((N=1; N<${#1}; N++)
                do
                        # Test each individual letter
                        case "${1:$N:1}" in
                        a)     echo "Got short option -a" >&2
                                ;;
                        *)
                                echo "Unknown short option ${1:$N:1}" >&2
                                exit 1
                                ;;
                         esac
                done
                ;;

        *)     echo "File arguments reached, stop shifting" >&2
                break
                ;;
        esac

        shift
done

if [ "$#" -eq 0 ]
then
        echo "No file arguments given" >&2
        exit 1
fi

echo "Operating on files" "$@"

do_stuff

exit 0

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