awk and sed are your friends.
'man awk'
'man sed'
On Wed, 4 Jul 2001, Paul Legato wrote:
> Hi,
> There are faster ways to do this with bash and sed, but the syntax is a bit
> more cryptic than Perl and it will only be negligibly faster on a job of
> 100 files or so.
>
> Crash Perl tutorial: Make a Perl script. Type the following in your favorite
> text editor and save it as sar.pl.
>
> -- begin cut --
> #!/usr/bin/perl -w
> # ^^ this line tells the kernel what scripting language interpreter to use
> # (in this case /usr/bin/perl with the -w "warnings on" switch. Your perl
> # might also be in /usr/local/bin/perl.)
>
> # Global variables.
> $original = "Jim";
> $changeto = "Jim H.";
>
>
> # Open the . directory (current directory) and associate it with the
> # filehandle DIR. Exit if unable to open.
> opendir DIR, "." or die "Don't have read access to current directory!";
>
>
> # foreach loops over the array and executes its code block
> # with $_ assigned each subsequent value of the array inside the ().
> # readdir DIR returns an array of the directory entries for DIR.
>
> foreach(readdir DIR)
> {
> open INFILE, "<$_"; # Open current filename for reading (the "<") and
> # associate with symbol "INFILE"
>
> open OUTFILE, ">$_.new"; # open new file for output
> # use the original filename with a .new extension
>
> # Print a warning and skip this file unless we got an INFILE and an OUTFILE
> # above.
> unless(INFILE and OUTFILE)
> {
> print "Couldn't process $_ -- skipping...\n"; #"\n" means newline
> next;
> } # end unless
>
> print "Processing $_..."; # notice no "\n" - stays on the same line
> # $_ will be replaced with the current filename
>
> while(<INFILE>) # The angle brackets <> read the next line from INFILE
> # into $_.
> { # while() repeats its block until there's a null inside the ()
> # (which is what happens with <> when you reach the
> # end of the file, EOF).
>
>
> s/$original/$changeto/g; # (s)earch for $original, change it to
> # $changeto, and make the search
> # (g)lobal (i.e. all occurances in the string)
>
> print OUTFILE $_; # Print the line to the output file
> } # end while
>
> print " Done.\n"; # print "Done." on the same line as "Processing..." above.
>
> close INFILE; # close the filehandles so they can be reused next loop.
> close OUTFILE;
>
> } # end foreach
>
> print "All done.\n";
> closedir DIR; # close the directory handle
>
> -- end cut --
>
> Then type "chmod +x sar.pl" to mark the script as executable by the kernel.
>
> Type "/path/to/sar.pl" to run it on the current directory. Note that you
> probably don't want to keep the file sar.pl itself in the directory you're
> running it on or else it will change the '$original = "Jim"' to '$original =
> "Jim H."'! It searches all files in the current directory for whatever
> $original is and write a new file called filename.new with all occurances of
> $original changed to $changeto.
>
> This is just the tip of the iceberg of what's possible with Perl. Check out
> http://www.perl.com/ and http://www.perldoc.com/ if you want to know more..
> This script could be modified without too much trouble to e.g., read its
> arguments (directory to process, $original, and $changeto) from the command
> line or to just modify the original file instead of creating another file
> with a .new extension (hint: use a temporary file with link and unlink)...
>
> Good luck..
> -Paul
>
>
>
>
> On Wednesday 04 July 2001 03:55 am, you wrote:
> > Non / soon to be member submission:
> > This may be simple, but i'm reading and reading and I can't find out
> > how. What i'm trying to do is a string replacement in many txt files at
> > once. Say theres 100 files with the name Jim in them and I want to
> > replace "Jim" with "Jim H". I can manually do it one by one with emacs,
> > but there may be thousands of needed replacements and that would take
> > OMG way too long.
> >
> > Any help?
> >
> > Thanks in advance.
>
------------------------------------------------------------------------
| Mark Bishop (mark@bish.net) | Computer Engineer |
| 813.258.2390 | Network Engineer |
| http://bish.net | Embedded Programmer |
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