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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

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Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

Commands tagged bash from sorted by
Terminal - Commands tagged bash - 733 results
h() { if [ -z "$1" ]; then history; else history | grep "$@"; fi; }
2009-10-13 21:49:37
User: haivu
Functions: grep
Tags: bash grep

Place this in your .bash_profile and you can use it two different ways. If you issue 'h' on its own, then it acts like the history command. If you issue:

h cd

Then it will display all the history with the word 'cd'

ping -q -c1 -w3 brandx.jp.sme 2&>1 /dev/null || echo brandx.jp.sme ping failed | mail -ne -s'Server unavailable' [email protected]
2009-10-13 14:13:04
User: mccalni
Functions: echo mail ping
Tags: bash ping mail

Joker wants an email if the Brand X server is down. Set a cron job for every 5 mins with this line and he gets an email when/if a ping takes longer than 3 seconds.

( trap '' 1; ( nice -n 19 sleep 2h && command rm -v -rf /garbage/ &>/dev/null && trap 1 ) & )

Check out the usage of 'trap', you may not have seen this one much. This command provides a way to schedule commands at certain times by running them after sleep finishes sleeping. In the example 'sleep 2h' sleeps for 2 hours. What is cool about this command is that it uses the 'trap' builtin bash command to remove the SIGHUP trap that normally exits all processes started by the shell upon logout. The 'trap 1' command then restores the normal SIGHUP behaviour.

It also uses the 'nice -n 19' command which causes the sleep process to be run with minimal CPU.

Further, it runs all the commands within the 2nd parentheses in the background. This is sweet cuz you can fire off as many of these as you want. Very helpful for shell scripts.

sed -i '19375 s/^/#/' file
2009-10-07 17:50:40
User: TuxOtaku
Functions: sed

This will comment out a line, specified by line number, in a given file.

env PS4=' ${BASH_SOURCE}:${LINENO}(${FUNCNAME[0]}) ' sh -x /etc/profile
su -- user
2009-09-28 04:23:43
User: matthewdavis
Functions: su
Tags: bash root su

I've used this a number of times troubleshooting user permissions. Instead of just 'su - user' you can throw another hyphen and stay in the original directory.

md () { mkdir -p "$@" && cd "$@"; }
2009-09-24 16:09:19
User: drewk
Functions: cd mkdir

How often do you make a directory (or series of directories) and then change into it to do whatever? 99% of the time that is what I do.

This BASH function 'md' will make the directory path then immediately change to the new directory. By using the 'mkdir -p' switch, the intermediate directories are created as well if they do not exist.

grep -RnisI <pattern> *
2009-09-22 15:09:43
User: birnam
Functions: grep
Tags: bash grep

This is how I typically grep. -R recurse into subdirectories, -n show line numbers of matches, -i ignore case, -s suppress "doesn't exist" and "can't read" messages, -I ignore binary files (technically, process them as having no matches, important for showing inverted results with -v)

I have grep aliased to "grep --color=auto" as well, but that's a matter of formatting not function.

`pbpaste` | pbcopy
2009-09-21 23:10:11
User: drewk
Tags: Os X bash osx pipes

The backtick operator, in general, will execute the text inside the backticks. On OS X, the pbpaste command will put the contents of the OS X clipboard to STDOUT. So if you put backticks around pbpaste, the text from the OS X clipboard is executed.

If you add the pipeline | pbcopy, the output from executing the command on the clipboard is placed back on the clipboard.

Note: make sure the clipboard is text only.

find $HOME -type f -print0 | perl -0 -wn -e [email protected]=<>; foreach $file (@f){ (@el)=(stat($file)); push @el, $file; push @files,[ @el ];} @o=sort{$a->[9]<=>$b->[9]} @files; for $i (0..$#o){print scalar localtime($o[$i][9]), "\t$o[$i][-1]\n";}'|tail
2009-09-21 22:11:16
User: drewk
Functions: find perl

This pipeline will find, sort and display all files based on mtime. This could be done with find | xargs, but the find | xargs pipeline will not produce correct results if the results of find are greater than xargs command line buffer. If the xargs buffer fills, xargs processes the find results in more than one batch which is not compatible with sorting.

Note the "-print0" on find and "-0" switch for perl. This is the equivalent of using xargs. Don't you love perl?

Note that this pipeline can be easily modified to any data produced by perl's stat operator. eg, you could sort on size, hard links, creation time, etc. Look at stat and just change the '9' to what you want. Changing the '9' to a '7' for example will sort by file size. A '3' sorts by number of links....

Use head and tail at the end of the pipeline to get oldest files or most recent. Use awk or perl -wnla for further processing. Since there is a tab between the two fields, it is very easy to process.

declare -ax CC; for i in `seq 0 7`;do ii=$(($i+7)); CC[$i]="\033[1;3${i}m"; CC[$ii]="\033[0;3${i}m"; done

I was looking for the fastest way to create a bunch of ansi escapes for use in echo -e commands throughout a lot of my shell scripts. This is what I came up with, and I actually stick that loop command in a function and then just call that at the beginning of my scripts to not clutter the environment with these escape codes, which can wreck havok on my terminal when I'm dumping the environment. More of a cool way to store escape ansi codes in an array. You can echo them like:

echo -e "${CC[15]}This text is black on bright green background."

I usually just use with a function:

# setup_colors - Adds colors to array CC for global use # 30 - Black, 31 - Red, 32 - Green, 33 - Yellow, 34 - Blue, 35 - Magenta, 36 - Blue/Green, 37 - White, 30/42 - Black on Green '30\;42' function setup_colors(){ declare -ax CC; for i in `seq 0 7`;do ii=$(($i+7));CC[$i]="\033[1;3${i}m";CC[$ii]="\033[0;3${i}m";done;CC[15]="\033[30;42m"; export R='\033[0;00m';export X="\033[1;37m"; }; export -f setup_colors

CC[15] has a background of bright green which is why it is separate. R resets everything, and X is my default font of bright white.

CC[15]="\033[30;42m"; R=$'\033[0;00m'; X=$'\033[1;37m'

Those are just my favorite colors that I often use in my scripts. You can test which colors by running

for i in $(seq 0 $((${#CC[@]} - 1))); do echo -e "${CC[$i]}[$i]\n$R"; done

See: http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html for more usage.

ss -p
2009-09-19 21:55:01
User: Escher

for one line per process:

ss -p | cat

for established sockets only:

ss -p | grep STA

for just process names:

ss -p | cut -f2 -sd\"


ss -p | grep STA | cut -f2 -d\"
seq -s " " -w 3 20
lsof -P -i -n | cut -f 1 -d " "| uniq | tail -n +2
(IFS=:;for p in $PATH; do test -d $p || echo $p; done)
2009-09-19 17:51:06
User: haivu
Functions: echo test
Tags: bash PATH

I often need to know of my directory in the PATH, which one DOES NOT exist. This command answers that question

* This command uses only bash's built-in commands

* The parentheses spawn a new sub shell to prevent the modification of the IFS (input field separator) variable in the current shell

netstat -lantp | grep -i stab | awk -F/ '{print $2}' | sort | uniq
2009-09-19 14:54:31
User: ProMole
Functions: awk grep netstat sort

Show apps that use internet connection at the moment.

Can be used to discover what programms create internet traffic. Skip the part after awk to get more details, though it will not work showing only unique processes.

This version will work with other languages such as Spanish and Portuguese, if the word for "ESTABLISHED" still contain the fragment "STAB"(e.g. "ESTABELECIDO")

netstat -lantp | grep -i establ | awk -F/ '{print $2}' | sort | uniq
netstat -lantp | grep -i establ | awk -F/ '{print $2}' | uniq | sort
2009-09-19 13:54:36
User: ktoso
Functions: awk grep netstat uniq

Can be used to discover what programms create internet traffic. Skip the part after awk to get more details.

Has anyone an idea why the uniq doesn't work propperly here (see sample output)?

echo -ne "\033]0;`id -un`:`id -gn`@`hostname||uname -n|sed 1q` `who -m|sed -e "s%^.* \(pts/[0-9]*\).*(\(.*\))%[\1] (\2)%g"` [`uptime|sed -e "s/.*: \([^,]*\).*/\1/" -e "s/ //g"` / `ps aux|wc -l`]\007"
2009-09-19 06:57:53
User: AskApache
Functions: echo

I usually have 5 or more ssh connections to various servers, and putting this command in my .bash_profile file makes my putty window or x terminal window title change to this easily recognizable and descriptive text. Includes the username, group, server hostname, where I am connecting from (for SSH tunneling), which device pts, current server load, and how many processes are running.

You can also use this for your PROMPT_COMMAND variable, which updates the window title to the current values each time you exec a command.

I prefix running this in my .bash_profile with

[[ ! -z "$SSH_TTY" ]] &&

which makes sure it only does this when connecting via SSH with a TTY.

Here's some rougher examples from http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

# If set, the value is executed as a command prior to issuing each primary prompt. #H=$((hostname || uname -n) 2>/dev/null | sed 1q);W=$(whoami) #export PROMPT_COMMAND='echo -ne "\033]0;${W}@${H}:${PWD/#$HOME/~} ${SSH_TTY/\/dev\//} [`uptime|sed -e "s/.*: \([^,]*\).*/\1/" -e "s/ //g"`]\007"' #PROMPT_COMMAND='echo -ne "\033]0;`id -un`:`id -gn`@`hostname||uname -n 2>/dev/null|sed 1q` `command who -m|sed -e "s%^.* \(pts/[0-9]*\).*(\(.*\))%[\1] (\2)%g"` [`uptime|sed -e "s/.*: \([^,]*\).*/\1/" -e "s/ //g"` / `command ps aux|wc -l`]\007"' #[[ -z "$SSH_TTY" ]] || export PROMPT_COMMAND #[[ -z "$SSH_TTY" ]] && [[ -f /dev/stdout ]] && SSH_TTY=/dev/stdout

And here's a simple function example for setting the title:

function set_window_title(){ echo -e "\033]0; ${1:-$USER@$HOST - $SHLVL} \007"; }
for p in ${PATH//:/ }; do [[ -d $p && -x $p ]] && echo $p; done
2009-09-19 06:43:57
User: AskApache
Functions: echo

Finds executable and existing directories in your path that can be useful if migrating a profile script to another system. This is faster and smaller than any other method due to using only bash builtin commands.

See also:

+ http://www.commandlinefu.com/commands/view/743/list-all-execs-in-path-usefull-for-grepping-the-resulting-list

+ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

printf "%02u " {3..20}; echo
2009-09-18 18:48:41
User: Escher
Functions: printf
Tags: bash strings

emulates bash4's "echo {03..20}"

Uses bash3 builtin function printf

for s in `seq -f %02.0f 5 15`; do echo $s; done
2009-09-18 13:21:38
User: Yeraze
Functions: echo
Tags: bash seq

Uses 'seq' with formatting parameter to generate the necessary padded sequence. Change '%02.0f' to how many digits you need (for 3, use %03.0f, etc) and replace 5 & 15 with your desired min and max.

for i in {0..1}{0..9}; do echo $i; done
2009-09-18 02:51:12
User: dennisw
Functions: echo
Tags: bash strings

Bash 4 will let you do {00..19} to get leading zeros, but Bash 3 doesn't have that feature. This technique gets you partway there (the sequences need be such that the last digit ranges from zero to nine - you can't use this for something like Bash 4's {03..27}, for example). When this limitation is not a problem, you can avoid some complicated string manipulation for concatenating leading zeros.

You can add more digits like this: {0..1}{0..9}{0..9} (ranges from 0 to 99 with up to two leading zeros). To pad with additional zeros:

for i in 000{0..1}{0..9}; do echo $i; done


for i in {0..1}{0..9}; do echo "000$i"; done

This is useful for creating values to sort or for creating filenames with a fixed format. Note that this will also work:

touch {0..1}{0..9}
budir=/tmp/bu.$$;for name in repMainPath/*/format;do dir=${name%/format};bufil=dumpPath/${dir##*/};svnadmin hotcopy --clean-logs $dir $budir;svnadmin dump --delta $budir>$bufil;rm -rf $budir;done
2009-09-16 01:34:48
User: arcege
Functions: dump
Tags: bash svn

Use of hotcopy for safety/stability of the backups.