Commands using perl (369)
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0alarm() { perl -e 'alarm shift; exec @ARGV' "$@"; }; alarm 20 foo arg1
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0perl -p -e 's/\$(\w+)/$ENV{$1}/g;' <files...>
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0perl -MYAML -MJSON -0777 -wnl -e 'print YAML::Dump(decode_json($_))' package.json
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0perl -MYAML -MJSON -0777 -wnl -e 'print YAML::Dump(decode_json($_))' package.json
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When trying to find an error in a hosted project it's interesting to find out how the source is organized: Are there .inc files? Or .php files only? Or .xml files that probably contain translated texts? Show Sample Output
0find . -type f | perl -ne 'chop(); $ext = substr($_, rindex($_, ".") + 1); print "$ext\n";' | sort | uniq --count | sort -n -
Lists directory size up to a maximum traversal depth on systems like IBM AIX, where the du command doesn't have Linux's --max-depth option. AIX's du uses -g to display directory size on gigabytes, -m to use megabytes, and -k to use kilobytes. tr### is a Perl function that replaces characters and returns the amount of changed characters, so in this case it will return how many slashes there were in the full path name. Show Sample Output
0du -g | perl -ne 'print if (tr#/#/# == <maximum depth>)' -
Does a search and replace across multiple files with a subgroup replacement.
0find . -name "*.txt" | xargs -n 1 perl -pi -w -e "s/text([0-9])/other\$1/g;" -
Note that in the command N is, for instance, 37. Show Sample Output
0perl -nle 'print length,"\t",$_ if length > 37' < /path/to/input/file -
If you have a logfile where some lines start with timestamps like "2014-05-01 12:34:56,123" but other lines are missing the timestamp (like stack traces or object dumps), then use this script to copy the most recent timestamp to any lines that are missing it. This is useful for merging log files, since you can then safely sort by timestamp to merge the files. Show Sample Output
0perl -ne 'if (/^(\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2},\d{3} )/ ) { $t=$1; print $_ } else { print $t . $_ }' -
Use case insensitive regex to match files ending in popular video format extensions and calculate their total time. (traverses all files recursively starting from the current directory) Show Sample Output
0find -type f -iregex '.*\.\(mkv\|mp4\|wmv\|flv\|webm\|mov\|dat\|flv\)' -print0 | xargs -0 mplayer -vo dummy -ao dummy -identify 2>/dev/null | perl -nle '/ID_LENGTH=([0-9\.]+)/ && ($t +=$1) && printf "%02d:%02d:%02d\n",$t/3600,$t/60%60,$t%60' | tail -n 1 -
0perl -M URI::Escape -lne 'print uri_unescape($_)'
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0perl -MPOSIX -le 'print strftime "%F", localtime 1234567890'
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I used this (along with a modified one replacing `mkv` with `srt`) to remove the slight differences in who the provider of the video / matching subtitle was (as they are the same contents and the subs match anyway). So now VLC (and other video players) can easily guess the subtitle file. Show Sample Output
0perl-rename -v 's/720p.+mkv/720p\.mkv/' *.mkv -
0finger $(whoami) | perl -ne '/Name: ([a-zA-Z0-9 ]{1,})/ && print "$1\n"'
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This will add a perl POD stub above each method in all modules found recursively in your current directory. The stub will look like: =head2 method_name =cut sub method_name { ...
0find . -type file -name '*.pm' | xargs perl -p -i -e 'BEGIN{undef $/;} s/([;}])\s*\nsub (\w+)/$1\n\n=head2 $2\n\n=cut\n\nsub $2/g' -
0tail -f /var/squid/logs/access.log | perl -pe 's/(\d+)/localtime($1)/e'
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0perl -E'say "#" x '$COLUMNS
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perl version of "Wait for file to stop changing" When "FileName" has not been changed for last 10 seconds, then print "DONE" "10" in "(stat)[10]" means ctime. One have other options like atime, mtime and others. http://perldoc.perl.org/functions/stat.html
0echo FileName | perl -nlE'sleep 1 while time-(stat)[10]<10' && echo DONE -
drop first column with perl "$#F" means a index of last column(start from 0). One can easily handle range of columns like "[3..6]"
0perl -anE'say join "\t",@F[1..$#F]' -
0grep page.php /var/log/httpd/access_log|awk '{print $1}'|sort|uniq|perl -e 'while (<STDIN>){chomp; $cmd=`ipset add banned -! -q $_`; }'
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This sequence of pipes will strip the last newline and send the remainder to the X11 clipboard. I have it as: alias clipb='perl -pe "chomp if eof" | xclip -selection c' so I can just do "echo hello | clipb" Multi-line texts will keep their internal newlines, but the last newline will be removed. This usually makes most sense. Show Sample Output
0echo $MYFILE | perl -pe "chomp if eof" | xclip -selection c -
Time protocol serves up seconds since 1900 in a 32 bit binary number. Show Sample Output
0telnet time.nist.gov 37 2>/dev/null |tail -1 | xxd | awk '{print $2 $3}'|tr -d '\n' | perl -nwe "print scalar(hex($1)-2208988800).\"\n\"" -
Sort your files in folders/chronological order Linux 4.1.6-1-ARCH Show Sample Output
0perl -MPOSIX=strftime -MFile::Path -e 'for(glob"*"){mkpath$d=strftime"%Y-%m-%d", localtime((stat)[9]);rename$_,"$d/$_"}' -
The only command-line version of this task I could come up with that properly handles UTF-8 input, too. (Yes, I know how crazy it is to have UTF-8 with HTML entity escapes, but that stuff exists... sadly...; Just check Twitter.)
0perl -C -MHTML::Entities -pe 'decode_entities($_);' -
Prints a string as a sequence of hexadecimal values. Output comes in space separated pairs, regardless of ASCII or Unicode characters Show Sample Output
0hexstring () { perl -p -e 's/(.)/sprintf("%02x", ord($1))/eg' << $1 } - ‹ First < 10 11 12 13 14 > Last ›
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