foreach question - UNIX for Dummies Questions & Answers

moldoverb · #1 (**permalink**) 01-07-2009

OK, so I am extremely rusty and am just getting back to Unix after 9 years.

I'm stuck on something easy. I want to search line-by-line for a string in a file, and I want to do this to a series of files in a directory.

This works fine to do the search:

while read i; do grep $i file2; done <file1.txt

This also works fine to read a directory:

foreach file ('/bin/ls *.txt')
echo $file
end

but if I try and combine the two, no joy.

foreach file ('/bin/ls *.txt')
while read i; do grep $i file2; done <$file
end

Help please!

pludi · #2 (**permalink**) 01-07-2009

Try this:

Code:

for file in `/bin/ls *.txt`
do
    while read i
    do
        grep $i file2
    done < $file
done

Of course, if your grep supports the -f switch you can try

Code:

for file in `find . -prune -name '*.txt' -print`
do
    grep -f $file $file2
done

HTH
/pludi

moldoverb · #3 (**permalink**) 01-07-2009

I get a 'bash: $file: ambiguous redirect ' in the first example.

pludi · #4 (**permalink**) 01-11-2009

Then rewrite the inner loop to

Code:

cat ${file} | while read i
do
    grep $i file2
done

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