find pattern in multiple files and perform some action on them - awk

Question

I have 2 files - file1.txt and file2.txt.
I want to set a condition such that, a command is run on both files only if a pattern "xyz" is present in both files. Even if one file fails to have that pattern, the command shouldn't run. Also , I need to have both files being passed to the grep or awk command at the same time as I am using this code inside another workflow language.
I wrote some code with grep, but this code performs the action even if the pattern is present in one of the files, which is not what I want . Please let me know if there is a better way to do this.
if grep "xyz" file1.txt file2.txt; then
my_command file1.txt file2.txt
else
echo " command cannot be run on these files"
fi
Thanks!

Answer 1

This awk should work for you:
awk -v s='xyz' 'FNR == NR {
if ($0 ~ s) {
++p
nextfile
}
next
}
FNR == 1 {
if (!p) exit 1
}
{
if ($0 ~ s) {
++p
exit
}
}
END {
exit p < 2
}' file1 file2
This will exit with 0 if given string is found in both the files otherwise it will exit with 1.

Answer 2

Salvaging code from a deleted answer by Cyrus:
if grep -q "xyz" file1.txt && grep -q "xyz" file2.txt; then
echo "xyz was found in both files"
else
echo "xyz was found in one or no file"
fi
If you need to run a single command, save this as a script, and run that script in your condition.
#!/bin/sh
grep -q "xyz" "$1" && grep -q "xyz" "$2"
If you save this in your PATH and call it grepboth (don't forget to chmod a+x grepboth when you save it) your condition can now be written
grepboth file1.txt file2.txt
Or perhaps grepall to accept a search expression and a list of files;
#!/bin/sh
what=$1
shift
for file; do
grep -q "$what" "$file" || exit
done
This could be used as
grepall "xyz" file1.txt file2.txt