Shell Programming and Scripting

Hi,

I need to write a perl script that should do a search recursively in all the '*.txt' files for the string "ALL -Tcb" and should print only the file names that do not contain this string.

Why Perl? It can be done, of course, but it sounds easier in shell.

Code:

find . -type f -name '*.txt' -print |
while read file; do
  grep -l "ALL -Tcb" "$file" >/dev/null && continue
  echo "$file"
done

If you have a grep which understands the -q option, use that instead of -l and the redirection to /dev/null.

Thanks era, but I am not using Unix or Linux machines rather Cygwin on windows. And it is a requirement for me to develop it only in Perl.

Hmm, this is a Unix forum ...?

Code:

perl -MFile::Find -e 'find(sub {
  return 0 unless (m/\.txt$/);  # skip file names which don't match this regex
  open (F, $File::Find::name) || warn "could not open $File::Find::name: $!\n";
  my $match = grep { /ALL -Tcb/ } <F>;
  close F;
  print "$File::Find::name\n" unless $match;
  return ! $match; }, ".")'

See the File::Find documentation for a bit of background. The grep will return a list of matching lines; because it is invoked in scalar context, that list will be turned into the number of elements in the list of matches. If that number is zero, there were none, and we print the file name.

The final parameter is the list of directories to traverse; simply "." will traverse the current directory and its subdirectories.

Thanks a lot era. If I run this script at command line of Cygwin, it is spewing lot many errors. So could you change it and give me as a perl program, so that I can run it from a file?

what errors do you see?

could not open ./api/group/file.txt: No such file or directory

like this continuously where ever txt files are found. I ran it by copying and pasting each and every line of the script (removed the comment)