Commands by cfajohnson

Commands by cfajohnson (19)

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Print today's date in ISO format without calling an external command (bash 4)
This is sample output - yours may be different.
2

today() { printf '%(%Y-%m-%d)T\n' -1; } ## bash-4

cfajohnson · 2013-01-27 06:17:25 7
Get MD5 checksum from a pipe stream and do not alter it
This is sample output - yours may be different.
2

tee >(openssl md5 > sum.md5) <somefile | bzip2 > somefile.bz2

cfajohnson · 2013-01-27 05:59:14 9
List only files in long format.
This is sample output - yours may be different.
0

ls -l | grep ^-

cfajohnson · 2010-03-20 03:20:19 5
Turn shell tracing and verbosity (set -xv) on/off with 1 command!

Turn shell tracing and verbosity (set -xv) on/off in any Bourne-type shell If either -x or -v is set, the function turns them both off. If neither is on, both are turned on.
This is sample output - yours may be different.
4

xv() { case $- in *[xv]*) set +xv;; *) set -xv ;; esac }

cfajohnson · 2010-02-14 20:57:29 4
floating point shell calculator
This is sample output - yours may be different.
0

calc() { awk 'BEGIN { OFMT="%f"; print '"$*"'; exit}'; }

cfajohnson · 2009-12-25 19:08:16 7
Recursive chmod all files and directories within the current directory
This is sample output - yours may be different.
5

chmod -R 774 .

cfajohnson · 2009-12-23 18:42:26 7
Random colours at random locations
This is sample output - yours may be different.
2

p(){ printf "\033[%d;%dH\033[4%dm \033[m" $((RANDOM%LINES+1)) $((RANDOM%COLUMNS+1)) $((RANDOM%8)); }; clear;while :;do p; sleep .001;done

cfajohnson · 2009-12-17 15:25:28 5
Optimal way of deleting huge numbers of files
This is sample output - yours may be different.
3

find /path/to/dir/ -type f -exec rm {} +

cfajohnson · 2009-12-10 04:44:44 52
Get your public ip
This is sample output - yours may be different.
-3

wget -qO - http://cfaj.freeshell.org/ipaddr.cgi

cfajohnson · 2009-12-10 04:34:57 4
Extract all urls from the last firefox sessionstore.js file used.
This is sample output - yours may be different.
-1

sed -e 's/{"url":/\n&/g' ~/.mozilla/firefox/*/sessionstore.js | cut -d\" -f4

cfajohnson · 2009-12-10 04:31:31 5
List files that DO NOT match a pattern

There's no need for ls or grep; printf is builtin to most modern shells
This is sample output - yours may be different.
-1

printf "%s\n" !(pattern) ## ksh, or bash with shopt -s extglob

cfajohnson · 2009-11-26 14:09:56 4
Shell function to exit script with error in exit status and print optional message to stderr

USAGE: die ERRNUM [MESSAGE]
This is sample output - yours may be different.
7

die(){ result=$1;shift;[ -n "$*" ]&&printf "%s\n" "$*" >&2;exit $result;}

cfajohnson · 2009-11-23 22:26:43 10
Find all dot files and directories

In most modern shells, printf is a builtin command.
This is sample output - yours may be different.
0

printf "%s\n" .*

cfajohnson · 2009-11-23 18:07:18 4
Make sure a script is run in a terminal.

Exit with error if script is not run in a terminal
This is sample output - yours may be different.
21

[ -t 0 ] || exit 1

cfajohnson · 2009-11-20 23:14:49 13
Get your external IP address
This is sample output - yours may be different.
0

wget -qO - http://www.sputnick-area.net/ip;echo

cfajohnson · 2009-11-20 23:10:31 5
List all available commands (bash, ksh93)
This is sample output - yours may be different.
7

printf "%s\n" ${PATH//:/\/* }

cfajohnson · 2009-11-20 22:55:59 5
force change password for all user

This assumes that te original's 'passwd -e' forces a user to change password; it doesn't in the versions I have.
This is sample output - yours may be different.
0

while IFS=: read u x; do passwd -e "$u"; done < /etc/passwd

cfajohnson · 2009-11-20 21:49:34 8
Find all dot files and directories
This is sample output - yours may be different.
1

printf "%s\n" .*

cfajohnson · 2009-11-20 21:41:02 4
Show sorted list of files with sizes more than 1MB in the current dir
This is sample output - yours may be different.
1

ls -l | awk '$5 > 1000000' | sort -k5n

cfajohnson · 2009-11-20 21:18:45 8

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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graphical memory usage

smem is very clever, it keeps in mind shared memory in its calculations!!! http://www.selenic.com/smem/

Update all packages installed via homebrew

As of March 7, 2012: $ brew update - downloads upgraded formulas $ brew upgrade [FORMULA...] - upgrades the specified formulas $ brew outdated - lists outdated installations Note updating all packages may take an excruciatingly long time. You might consider a discriminating approach: run `brew outdated` and select specific packages needing an upgrade. For more information see homebrew's git repository: https://github.com/mxcl/homebrew

Compute the numeric sum of a file

In the file data.txt there is a single column of numbers. Sed adds a "+" between lines and xargs prepares the output for bc. The "echo 0" is to avoid to have a "+" at the beginning of the line.

Stream youtube videos

Streams youtube-dl video to mplayer. Usage: syt 'youtube.com/link' 'anotherlinkto.video' Uses mplayer controls

Extract your list of blocked images hosts from Firefox database

I use this to replicate my blocked images hosts list between work and home to keep my browsing ad-free.

Find unused IPs on a given subnet

See system users

check open ports without netstat or lsof

Get AWS temporary credentials ready to export based on a MFA virtual appliance

You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Execute a command with the last parameter of a previous command

Suppose that you had change in a directory like /home/user/mycode/code, and now you need to list it, instead of type entire path again, use ls !$ to recall path and list. Useful with many commands, this is only an example. (In this case, same result can be achivied with ls .)

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