Finding multiple strings in shell scripts

Question

I am trying to find strings Error:, Error :, ERROR:, ERROR : in a given file, if found then go to if block if not found then go to else block.

Below is the logic I had written to perform this operation.

#!/bin/bash
file='file.log'
text=`cat $file`
echo $text
if [[ ${text} = *Error:* ||${text} = *ERROR:*|| ${text} = *ERROR :* || ${text} = *Error :* || $? -ne 0 ]]; then
  STATUS=1
  echo "=> string found." 
else
  echo "=> no string found." 
fi

Seems like this logic is having issues as its returning below error.

syntax error near `:*'

Can someone please help me in resolving this issue?

Thats indeed a good question, i tried even this it didnt work for me. Please bear with me as i am new to shell scripting. — Jennie
– Jennie, Commented May 9, 2022 at 11:03
if ( grep -iq 'error \{0,1\}:' $value || $? -ne 0; ) ; then STATUS=1 echo "=> found string." else echo "=> Didnt found string." fi — Jennie
– Jennie, Commented May 9, 2022 at 11:07

Biffen · Accepted Answer · 2022-05-09 11:10:57Z

1

The pattern you’re looking for is easily expressed in a regex, so you can just use grep:

#!/bin/bash

file='file.log'

if grep -iq 'error \{0,1\}:' "${file}"
then
  STATUS=1
  echo "=> string found." 
else
  echo "=> no string found." 
fi

There’s no need to read the whole file into a variable, nor to check $? explicitly.

answered May 9, 2022 at 11:10

Biffen

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Thomas · Accepted Answer · 2022-05-10 06:56:06Z

1

This is easier to do using grep, using -i for case insensitive matching and -q to suppress output:

#!/bin/bash
file='file.log'
if grep -iq 'error \?:' "$file"; then
  STATUS=1
  echo "=> string found." 
else
  echo "=> no string found." 
fi

The regular expression error ?: means: the text error, followed by an optional space (indicated by \? after the space), followed by :.

edited May 10, 2022 at 6:56

answered May 9, 2022 at 11:10

Thomas

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2 Comments

Jennie Over a year ago

thanks thomas, eventhough i updated my logic still its going to else block.

Thomas Over a year ago

Sorry, missed a backslash there, fixed now (and tested :)).

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