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Closed 6 years ago.
Say we have two files: a.txt and b.txt. Each file has multiple lines of text.
How do I write a shell script to check if all of the content of a.txt exists in b.txt?
Thx for the hints guys, i didn't noticed -q will output 0 if successfully matched.
I end up with:
if grep a.txt -q -f b.txt ; then
else
fi
Here is a script that will do what what you are describing:
run: sh SCRIPT.sh a.txt b.txt
# USAGE: sh SCRIPT.sh TEST_FILE CHECK_FILE
TEST_FILE=$1
CHECK_FILE=$2
## for each line in TEST_FILE
while read line ; do
## check if line exist in CHECK_FILE; then assign result to variable
X=$(grep "^${line}$" ${CHECK_FILE})
## if variable is blank (meaning TEST_FILE line not found in CHECK_FILE)
## print 'false' and exit
if [[ -z $X ]] ; then
echo "false"
exit
fi
done < ${TEST_FILE}
## if script does not exit after going through each line in TEST_FILE,
## then script will print true
echo "true"
Assumptions:
- line order from a.txt does not matter
You need to write a loop that iterates over each line in a.txt and use grep (or some other means) to see if that line is in b.txt. If you find any instance where it is not in b.txt, then you can provide the answer: not all lines match. If you find no such instances, you can conclude that all lines match.
Capturing the output of grep using backticks would likely be useful:
if [`grep -v $line b.txt`== ""]; then
kind of thing.
If you have specific questions about how to iterate over the contents of a file, you should ask a specific question about that, showing what you tried.
