mjhjmtu

I have 23 strings to search, I want it returns those that are in the file.

I got the code below:

users='User1|User2|User3|User4|User5|User6|User7|User8|User9|User10|User11|User12..User23'

Desired output:

User1 is in the file
User2 is not in the file
...
User 23 is in the file

I have no idea how to make it, I was thinking in an array but, I want some tips if is possible. Thanks in advance.

Try this,

users=( User1 User2 User3 User4 )
for i in "$users[@]"
do
 grep -qw $i file && echo "$i is in the file" || echo "$i is not in the file"
done

From man:

-q, --quiet, --silent

Quiet; do not write anything to standard output. Exit immediately with zero status if any match is found, even if an error was detected.

Use an array:

users=(User1 User2 User3 User4) # et cetera
for i in "$users[@]"; do
 echo -n "$user is "
 if grep -q "$user" inputfile; then
 echo "present"
 else
 echo "not present"
 fi
done

grep -q will execute the search but not return any output, allowing you to use it silently in an if test.

Alternatively, you can put each user on its on line in a file called Users, and then:

grep -o -f Users inputfile

This will output a list of all users seen. If you want to see both present and absent users, you could:

echo "Users present:"
grep -o -f Users inputfile
echo "Users absent:"
grep -vo -f Users inputfile

A further tweak.

users=( User1 User2 User3 User4 )
for i in "$users[@]"
do
 echo "$i is" $(grep -qw $i file || echo "not") "in the file"
done

With only a single scan through the file: this is bash

# the array of user names
users=( User1..23 )
# an array of grep options: ( -e User1 -e User2 ...)
for u in "$users[@]"; do grep_opts+=( -e "$u" ); done
# scan the input file and save the user names that are present in the file
readarray -t users_present < <(grep -Fo "$grep_opts[@]" input | sort -u)
# find the user names absent from the file
# this assumes there are no spaces in any of the user names.
for u in "$users[@]"; do
 [[ " $users_present[*] " == *" $u "* ]] || users_absent+=( "$u" )
done
# and print out the results
printf "%s is in the filen" "$users_present[@]"
printf "%s is NOT in the filen" "$users_absent[@]"