On Mon, 18 August 2014, at 10:42 am, wraeth <[email protected]> wrote:
> On Mon, 2014-08-18 at 18:54 +1000, Adam Carter wrote:
>> But this matches if grep fails both times as well as when it matches both
>> time. Any ideas?
>
> If you don't mind using a quick loop, you could use something like:
>
> n=0
> for f in file1.txt file2.txt file3.txt file4.txt; do
> grep 'string' ${f} >> /dev/null && n=$[n+1]
> done
>
> if [[ $n == 4 ]]; then
> do_something
> fi
I've solved similar problems the same way myself, but I hope you'll forgive me
for offering unsolicited critique on a small detail.
In the above 4 is a constant, and thus it's independent of the number of files
being tested.
I propose addressing this with an array of the filenames.
Thus additional files can be added for testing, without manual adjustment of
the expected total.
files=("file1.txt" "file2.txt" "file3.txt" "file4.txt")
n=0
for f in ${files[@]}; do
grep 'string' ${f} >> /dev/null && n=$[n+1]
done
if [[ $n == ${#files[@]} ]]; then
do_something
fi
Bash array syntax is a bit arcane, but at least these very useful data
structures are available.
Stroller.
