get command line perl command to report what changes it's made

Question

I am using the following command (on Solaris) to remove the protocol from a bunch of files.

find .  -name "*.txt"  -exec perl -pi  -e 's/http//g' '{}' \;

Is there a way to have a verbose output so I can get a report of which files have been edited?

Thanks, Andy

Stéphane Chazelas · Accepted Answer · 2015-11-06 16:56:42Z

3

You could get a count of substitutions per file with:

find . -type f -exec perl -pi -e '
    $count{$ARGV} += s/http//g;
    END {for (keys %count) {print "$_: $count{$_}\n" if $count{$_}}}' {} +

Note that in that and in your original solution, perl will rewrite the files regardless of whether it does substitution in them or not.

Don't use ; to terminate the -exec command. perl can handle several files at a time, no need to call one perl per file.

If you only want that output without actually doing the substitutions, just replace -pi with -n in the command above.

You could also do:

find . -type f -exec grep -c http /dev/null {} +

To get a count of lines containing http (not necessarily the same as the number of http occurrences).

answered Nov 6, 2015 at 16:32

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glenn jackman · Accepted Answer · 2015-11-06 22:30:08Z

1

You can get a report of what files are sent to perl by using both -print and -exec:

find .  -name "*.txt" -print -exec perl -pi  -e 's/http//g' '{}' \;

If you want to find out which files were modified, then something like

find .  -name "*.txt" \
    -exec perl -i.bak -pe 's/http//g' '{}' \; \
    -exec sh -c 'cmp -s "$1" "$1.bak" && echo "$1" || rm "$1.bak"' _ '{}' \;

answered Nov 6, 2015 at 22:30

glenn jackman

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2 Answers 2