Commands using perl sorted by votes

Commands using perl (369)

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Calculate the mean or average of a single column of numbers in a text file

single-column-numbers.txt is a text file with 22658 rows (numbers) in a single column. Each number can range from 0 to 134298679.533591 and the dot is for the decimals. This is done with perl because awk can't sum such high numbers. Show Sample Output
This is sample output - yours may be different.
```
87553740.0874476
```
1

perl -lane '$total += $F[0]; END{print $total/$.}' single-column-numbers.txt

bugmenot · 2021-06-30 07:45:56 164
infile search and replace on N files

The "g" at the end is for global, meaning replace all occurrences and not just the first one.
This is sample output - yours may be different.
0

perl -pi -e's/foo/bar/g' file1 file2 fileN

xsawyerx · 2009-01-29 09:47:01 61
creates a bash function to remove certain lines from SSH known_hosts file

sometimes you got conflicts using SSH (host changing ip, ip now belongs to a different machine) and you need to edit the file and remove the offending line from known_hosts. this does it much easier. Show Sample Output
This is sample output - yours may be different.
```
$ sshdel 30
< removes 30th line from the known_hosts file in ~/.ssh >
```
0

function sshdel { perl -i -n -e "print unless (\$. == $1)" ~/.ssh/known_hosts; }

xsawyerx · 2009-02-03 16:20:50 52
Replaces every ocurrences of 'old' for 'new' in all files specified

Replaces every ocurrence of 'old' for 'new' in all files specified. After the 'i' char you can put a '~' or whatever to create a backup file for each replaced with the name equal to the original plus character.
This is sample output - yours may be different.
0

perl -i -pe "s/old/new/g" *

pandres · 2009-02-05 12:07:27 66
simple perl global search and replace in files
This is sample output - yours may be different.
0

perl -pi -e 's/localhost/replacementhost/g' *.php

sunkencity · 2009-02-05 15:26:12 24

Quick command to check if Perl library is installed on your server. Show Sample Output

perl -e "use SOAP::Lite"

leprasmurf · 2009-02-06 15:26:37 16

hello, world

quoted from http://0-9.sakura.ne.jp/blog/archives/2008/10/29121116.html
This is sample output - yours may be different.
0

perl -e "''=~('(?{'.('-^@.]|(;,@/{}/),[\\\$['^'],)@)[\`^@,@[*@[@?}.|').'})')"

wbx · 2009-02-08 10:42:02 14
Strip out Hungarian notation from a PHP file

This removes the type prefix used in Hungarian notation (v. bad) for PHP variables. Eg. variables of the form $intDays, $fltPrice, $arrItems, $objLogger convert to $days, $price, $Items, $logger.
This is sample output - yours may be different.
0

cat file.php | perl -p -e 's/(\$|->)(str|arr|obj|int|flt|boo|bool|mix|res)([A-Z])/$1\L$3/g'

root · 2009-02-10 14:37:12 11
Add a newline to the end of a cpp file

Adds a newline to the end of all cpp files in the directory to avoid warnings from gcc compiler.
This is sample output - yours may be different.
0

find . -iname "*.cpp" -exec perl -ni -e 'chomp; print "$_\n"' {} \;

grundprinzip · 2009-02-18 14:12:24 7
dos2unix

Converts windows lined-style file to unix. see http://en.wikipedia.org/wiki/Newline Can be used to convert from linux2dos : just invert \r\n and \n.
This is sample output - yours may be different.
0

$ perl -pi -e 's/\r\n/\n/g' <finelame>

unixmonkey4200 · 2009-04-10 22:22:31 8
Rearrange words from a file

Consider this line : random perl language this make possible is is possible to rearrange words with $F perl variable and word index, starting from 0. Show Sample Output
This is sample output - yours may be different.
```
#  perl -lane 'print "$F[3] $F[6] $F[2]"' myfile 
this is perl
```
0

perl -lane 'print "$F[0]:$F[1]:$F[2]"' myfile

servermanaged · 2009-05-09 21:30:55 4
get the list of temps for your hard-drives

get a list of temps of your hard-drives. Show Sample Output
This is sample output - yours may be different.
```
31 31 31 29
```
0

hddtemp /dev/sda /dev/sdb /dev/hda /dev/hdb | gawk '{print $NF}' | perl -n -e '$_ =~ s/(\d+)/print "$1 "/eg }{ print "\n"'

microft · 2009-05-20 16:01:58 4
Print multiline text starting and ending at specific regexps with perl

Using perl, here, we grep the man page of fetchmail to find the paragraph starting with '-k | --keep' and ending before the paragraph starting with '-K | --nokeep' Show Sample Output
This is sample output - yours may be different.
```
-k | --keep
              (Keyword:  keep)  Keep  retrieved messages on the remote mailserver.  Normally, messages are deleted from the folder on the mailserver after they have been retrieved.  Specifying
              the keep option causes retrieved messages to remain in your folder on the mailserver.  This option does not work with ETRN or ODMR. If used with POP3, it is recommended  to  also
              specify the --uidl option or uidl keyword.

       
```
0

man fetchmail | perl -ne 'undef $/; print $1 if m/^.*?(-k \| --keep.*)-K \| --nokeep.*$/smg'

unixmonkey4437 · 2009-06-25 23:51:35 10
Test if the given argument is a valid ip address.

This command will output 1 if the given argument is a valid ip address and 0 if it is not. Show Sample Output
This is sample output - yours may be different.
```
1
```
0

perl -e '$p=qr!(?:0|1\d{0,2}|2(?:[0-4]\d?|5[0-5]?|[6-9])?|[3-9]\d?)!;print((shift=~m/^$p\.$p\.$p\.$p$/)?1:0);' 123.123.123.123

speaker · 2009-07-12 00:24:29 3
get events from google calendar for a given dates range

substitute the URL with your private/public XML url from calendar sharing settings substitute the dates YYYY-mm-dd adjust the perl parsing part for your needs Show Sample Output
This is sample output - yours may be different.
```
Claudio,2009-07-30
Claudio,2009-07-23
Claudio,2009-07-17
Claudio,2009-07-16
Claudio,2009-07-10
Claudio,2009-07-03
Claudio,2009-07-02
Claudio,2009-06-26
Claudio,2009-06-25
Failure,2009-06-20
Glconsulting,2009-06-18
Failure,2009-06-15
production migration,2009-06-08
```
0

wget -q -O - 'URL/full?orderby=starttime&singleevents=true&start-min=2009-06-01&start-max=2009-07-31' | perl -lane '@m=$_=~m/<title type=.text.>(.+?)</g;@a=$_=~m/startTime=.(2009.+?)T/g;shift @m;for ($i=0;$i<@m;$i++){ print $m[$i].",".$a[$i];}';

unixmonkey4704 · 2009-07-23 14:48:54 4
replace old htaccess php AddHandler values with new one

Alter "AddHandler php5-cgi .php" and "AddHandler php4-cgi .php" entries to new "AddHandler x-httpd-php5 .php" respective php4 entries in all .htaccess files under /var/www Show Sample Output
This is sample output - yours may be different.
```
-
```
0

find /var/www/ -type f -name ".htaccess" -exec perl -pi -e 's/AddHandler[\s]*php(4|5)-cgi/AddHandler x-httpd-php\1/' {} \;

foob4r · 2009-08-21 21:55:22 3
Download entire commandlinefu archive to single file

This is an extension of a previous command by satyavvd on 2009-07-23 12:04:02, but this one grabs the whole archive. Hard coded numbers in previous script capped number of commands that could be fetched. This one grabs them all regardless of how big the archive gets. Show Sample Output
This is sample output - yours may be different.
```
# SSH connection through host in the middle
ssh -t reachable_host ssh unreachable_host

# A fun thing to do with ram is actually open it up and take a peek. This command will show you all the string (plain text) values in ram
sudo dd if=/dev/mem | cat | strings

# Watch Star Wars via telnet
telnet towel.blinkenlights.nl

# Backticks are evil
echo "The date is: $(date +%D)"
```
0

for x in `jot - 0 \`curl "http://www.commandlinefu.com/commands/browse"|grep "Terminal - All commands" |perl -pe 's/.+(\d+),(\d+).+/$1$2/'|head -n1\` 25`; do curl "http://www.commandlinefu.com/commands/browse/sort-by-votes/plaintext/$x" ; done >a.txt

stinkerweed999 · 2009-08-25 21:57:15 6
Find all PowerPC applications on OS X

This finds all the PowerPC apps recognized by OS X. A better version is: system_profiler SPApplicationsDataType 2> /dev/null | perl - wnl -e '$i=$j=$k=$p=0; @al=; $c=@al; while($j s[$i].=$al[$j]; $i++ if ($al[$j]) =~ /^\s\s\s\s\S.*:$/; $j++} while($k apps[$k++]; if (/Kind: PowerPC/s) {print; $p++;}} print "$i applications, $p P owerPC applications\n\n"' but that is more than 255 characters...
This is sample output - yours may be different.
0

system_profiler SPApplicationsDataType | perl -nl -e '@al=<>; $c=@al; while($j<$c){ $apps[$i].=$al[$j]; $i++ if ($al[$j] ) =~ /^\s\s\s\s\S.*:$/; $j++} while($k<$i){ $_=$apps[$k++]; if (/Kind: PowerPC/s) {print;}}'

drewk · 2009-09-06 20:56:48 8
print scalar gmtime

print scalar gmtime
This is sample output - yours may be different.
0

perl -e "print scalar(gmtime(1247848584))"

opexxx · 2009-09-11 06:19:09 17
Fix UTF-8 text files misinterpreted as ISO 8859-1 due to Byte Order Mark (BOM) of the Unicode Standard.

Fixes the faulty files with perl, which may exist on more platforms
This is sample output - yours may be different.
0

perl -i -pe 's/\xef\xbb\xbf//g' <file>

pfredrik · 2009-09-15 11:22:43 4
Dump all of perl's config info

This dumps all of your installed perl's config information.
This is sample output - yours may be different.
0

perl -le 'use Config; foreach $i (keys %Config) {print "$i : @Config{$i}"}'

chuckr · 2009-09-22 22:14:21 4
Show which include directories your installation of Perl is using.

This will show where your Perl installation is looking for modules.
This is sample output - yours may be different.
0

perl -le 'print join $/, @INC'

chuckr · 2009-09-22 22:18:35 6
Randomize lines (opposite of | sort)

The sort utility is well used, but sometimes you want a little chaos. This will randomize the lines of a text file. BTW, on OS X there is no | sort -R option! There is also no | shuf These are only in the newer GNU core... This is also faster than the alternate of: | awk 'BEGIN { srand() } { print rand() "\t" $0 }' | sort -n | cut -f2- Show Sample Output
This is sample output - yours may be different.
```
cat ~/SortedFile.txt | perl -wnl -e '@f=<>; END{ foreach $i (reverse 0 .. $#f) { $r=int rand ($i+1); @f[$i, $r]=@f[$r,$i] unless ($i==$r); }  chomp @f; foreach $line (@f){ print $line; }}'

... randome lines from SortedFile.txt
```
0

cat ~/SortedFile.txt | perl -wnl -e '@f=<>; END{ foreach $i (reverse 0 .. $#f) { $r=int rand ($i+1); @f[$i, $r]=@f[$r,$i] unless ($i==$r); } chomp @f; foreach $line (@f){ print $line; }}'

drewk · 2009-09-24 15:42:43 5
google search

not my cmd... found on the web Show Sample Output
This is sample output - yours may be different.
```
  12. http://g33kinfo.com/
  15. http://g33kinfo.com/info/?p=386
  18. http://g33kinfo.com/info/?p=440
  20. http://g33kinfo.com/info/?p=441
  22. http://g33kinfo.com/info/?p=288
  25. http://g33kinfo.com/info/?p=355
  28. http://g33kinfo.com/info/?p=327
  31. http://g33kinfo.com/info/?p=400
  34. http://g33kinfo.com/info/?p=102
  37. http://g33kinfo.com/info/?p=402
```
0

perl -e '$i=0;while($i<10){open(WGET,qq/|xargs lynx -dump/);printf WGET qq{http://www.google.com/search?q=site:g33kinfo.com&hl=en&start=$i&sa=N},$i+=10}'|grep '\/\/g33kinfo.com\/'

op4 · 2009-10-16 12:20:17 7
List your largest installed packages (on Debian/Ubuntu)

List packages and their disk usage in decreasing order. This uses the "Installed-Size" from the package metadata. It may differ from the actual used space, because e.g. data files (think of databases) or log files may take additional space. Show Sample Output
This is sample output - yours may be different.
```
342348  netbeans-ide
231728  kdelibs4-doc
121332  comixcursors
108796  openoffice.org-core
[...]
```
0

perl -ne '$pkg=$1 if m/^Package: (.*)/; print "$1\t$pkg\n" if m/^Installed-Size: (.*)/;' < /var/lib/dpkg/status | sort -rn | less

hfs · 2009-10-19 12:55:59 7
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Find the package that installed a command

directly ssh to host B that is only accessible through host A

Of course you need to be able to access host A for this ;-)

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

get you public ip address

Relies on ifconfig.me functioning. It's about as easy as it gets, and memorable to old geeks too.

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Make a server's console beep when the network is down

This is like ping -a, but it does the opposite. It alerts you if the network is down, not up. Note that the beep will be from the speaker on the server, not from your terminal. Once a second, this script checks if the Internet is accessible and beeps if it is not. I define the Net as being "UP", if I can ping Google's public DNS server (8.8.8.8), but of course you could pick a different static IP address. I redirect the beep to /dev/console so that I can run this in the background from /etc/rc.local. Of course, doing that requires that the script is run by a UID or GID that has write permissions to /dev/console (usually only root). Question: I am not sure if the -W1 flag works under BSD. I have only tested this under GNU/Linux using ping from iputils. If anybody knows how portable -W is, please post a comment.

Split video files using avconv along keyframes

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Geolocate a given IP address

GeoIP Needs to be installed. Can be done from some distro's or via MaxMind.com for free. There even is a free city database availabble. If the GeoLiteCity is downloaded and installed it will also find more information $ geoiplookup -f /var/lib/GeoIP/GeoLiteCity.dat commandlinefu.com GeoIP City Edition, Rev 1: US, NJ, Absecon, 08201, 39.420898, -74.497704, 504, 609

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Commands using perl (369)

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