Shell Script to Check If a Paragraph/Stream of Lines Exist in a File

Shell script to check if a paragraph/stream of lines exist in a file

Typically , these are not the same.
The grep var $result, contains new line (\n) characters inside, while the $line contains spaces.

If you set IFS=$"\n" before echo $result, you will be able to see the difference between them.

I had to insert some \n to $line (in the correct position) and now works fine:

#!/bin/bash
result=$(cat test.log | grep -A 2 "Published 1EO's")
IFS=$"\n"
echo $result
line=$(echo -e "Published 1EO's\nSave completed\nTrade saving save successful for trade 56945458|220841|b for MCR: CMDTY from source:ICE Tradecapture API retry count: 0 (From this line we check Company Name – CMDTY)")
echo "----------------------------------"
#echo $line | grep "\b$result\b"
echo $line

unset IFS

if [[ $line = $result ]]; then
 echo "match"
else
 echo "does not match"
fi

Result:

$./bashtest.sh
Published 1EO's
Save completed
Trade savi g save successful for trade 56945458|220841|b for MCR: CMDTY from source:ICE Tradecapture API retry cou t: 0 (From this li e we check Compa y Name – CMDTY)
----------------------------------
Published 1EO's
Save completed
Trade savi g save successful for trade 56945458|220841|b for MCR: CMDTY from source:ICE Tradecapture API retry cou t: 0 (From this li e we check Compa y Name – CMDTY)
match

Shell script to check if a paragraph exist in a file

With sed:

$ output=$(sed -n "/Published 3EO's/N;{/Save completed/N;{/Trade saving save successful for 123/p}}" file)
$ echo "$output"
Published 3EO's
Save completed
Trade saving save successful for 123

Shell script to check if a paragraph exist in a file

With sed:

$ output=$(sed -n "/Published 3EO's/N;{/Save completed/N;{/Trade saving save successful for 123/p}}" file)
$ echo "$output"
Published 3EO's
Save completed
Trade saving save successful for 123

How can I read words (instead of lines) from a file?

The read command by default reads whole lines. So the solution is probably to read the whole line and then split it on whitespace with e.g. for:

#!/bin/sh

while read line; do
    for word in $line; do
        echo "word = '$word'"
    done
done <"myfile.txt"

bash text search: find if the content of one file exists in another file

try grep

cat b.txt|grep -f a.txt

Read n lines at a time using Bash

This is harder than it looks. The problem is how to keep the file handle.

The solution is to create another, new file handle which works like stdin (file handle 0) but is independent and then read from that as you need.

#!/bin/bash

# Create dummy input
for i in $(seq 1 10) ; do echo $i >> input-file.txt ; done

# Create new file handle 5
exec 5< input-file.txt

# Now you can use "<&5" to read from this file
while read line1 <&5 ; do
        read line2 <&5
        read line3 <&5
        read line4 <&5

        echo "Four lines: $line1 $line2 $line3 $line4"
done

# Close file handle 5
exec 5<&-

Match two strings in one line with grep

You can use

grep 'string1' filename | grep 'string2'

Or

grep 'string1.*string2\|string2.*string1' filename

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