Question

Simple shell scripting

Write a Bash shell script called strcount.sh that counts the number of occurances of a given string within a file. The scripts takes two arguments: the name of the file to check and the string to count occurances of. If the file is not found (or not readable), the script should print the error message Cannot access file and exit with code -1. Otherwise, the script should print the number of occurances of the given string and exit with code 0. If the user fails to specify two arguments, the script should print the error message Usage: strcount.sh <file> <string> and exit with code -1.

Thus, if I have the following file penguins.txt:

  Galapagos penguin
  Erect-crested penguin
  Subantarctic gentoo penguin
  Royal penguin
  Humboldt penguin
  Eastern rockhopper penguin
  Fiordland penguin
  Allied king penguin
  Ellsworth's gentoo penguin
  White-flippered penguin
  Cook Strait little penguin
  Chatham Island little penguin

Then the output should be the following:

  ekrell@ekrell-desktop:~$ ./strcount.sh penguins.txt little
  2

Or if the file does not exist:

  ekrell@ekrell-desktop:~$ ./strcount.sh badfile.txt little
  Cannot access file

Or if the user fails to specify two arguments:

  ekrell@ekrell-desktop:~$ ./strcount.sh 
  Usage: strcount.sh <file> <string>

Write your script here

  <- ... ->
  <- ... ->
  <- ... ->
  <- Add as many lines as you need ->

Credit

Material adopted from http://faculty.smu.edu/hdeshon/

Answer 1

check out the solution and do COMMENT if any queries.

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#!/bin/bash

# check for 2 arguments along with strcount.sh

# if there no arguments then print appropriate message

if [ "$#" -ne 2 ]; then

        echo "Usage : strcount.sh <file> <string>"

        exit -1

else

        # if arguments are present then read them in variables

        filename=$1

        str=$2

        # check if file exists

        if [ ! -f "$filename" ]; then

                echo "Cannot access file"

                exit -1

        else

                # grep - searches for the given string in given file

                # -wc : word count

                count=$(grep -wc "$str" "$filename")

                # print the count

                echo "$count"

                exit 0

        fi

fi

# program ends

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OUTPUT ::

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contents of penguins.txt