Commands using echo sorted by votes

Commands using echo (1,545)

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cd to (or operate on) a file across parallel directories

ksh's version of cd has an optional syntax where you can type "cd old new" and it will replace "old" with "new" in your current directory and take you there. This is very handy when you have a parallel directory structure, like source and object directories. As suggested, you can just type cd ${PWD/old/new} to get this in bash, but this function in your .bashrc will let you type the ksh cd syntax and avoid typing the special characters while preserving other cd functionality. Show Sample Output
This is sample output - yours may be different.
```
splante@guinness:/tmp/src/x/y/z/> cd src obj
splante@guinness:/tmp/obj/x/y/z/> cd obj src
splante@guinness:/tmp/src/x/y/z/> 
```
0

cd () { cdop=""; while [ "$1" != "${1#-}" ]; do cdop="${cdop} ${1}"; shift; done; if [ $# -eq 2 ]; then newdir="${PWD/$1/$2}"; [ -d "${newdir}" ] || { echo "no ${newdir}"; return 1; }; builtin cd $cdop "${newdir}"; else builtin cd $cdop "$@"; fi }

splante · 2011-04-07 14:36:26 3
List your MACs address
This is sample output - yours may be different.
0

echo | ifconfig | grep HWaddr

malto · 2011-04-12 23:59:54 3
resolve hostname to IP our vice versa with less output

The host command comes with the bind-utils package, which is has a better chance to be installed than resolveip from mysql. The last word of the query result is displayed, which is the last result host got. This works with CNAMEs. You get "3(NXDOMAIN)" in case of failure. Show Sample Output
This is sample output - yours may be different.
```
192.0.32.10
```
0

hostresult=$(host -t A www.example.com); echo "${hostresult##* }"

kilx · 2011-04-21 10:16:50 4
un-escape URL/URIs with Ruby
This is sample output - yours may be different.
0

echo 'example.com%2Fsome%2Fpath' | ruby -r'cgi' -e 'puts CGI.unescape(STDIN.read)'

slippyd · 2011-04-26 03:13:22 3
replace one of the octates of an IP

the numbers in the ip address are represented in sed as \1\2\3\4. If I put \1\2\3$i, then I change the last number. So for example to change the second number I'll do \1$i\3\4. Regards, Kfir Show Sample Output
This is sample output - yours may be different.
```
10.0.0.3
```
0

i=3; echo 10.0.0.1 | sed "s/$[0-9]\{1,3\}\.$$[0-9]\{1,3\}\.$$[0-9]\{1,3\}\.$$[0-9]\{1,3\}$/\1\2\3$i/g"

kipibenkipod · 2011-04-27 14:08:02 3
print line and execute it in BASH

since we're repeating the command there after the semicolon, we only need one backtick Show Sample Output
This is sample output - yours may be different.
```
$ echo "ls"; `!#:0-$

echo "ls"; `echo "ls" ; `
ls
Android.mk  ardrv  devmgr  egl  file1
```
0

$ echo "command"; `!#:0-$

unixmonkey20949 · 2011-04-28 17:09:25 3
Persistent saving of iptables rules

Should run with sudo
This is sample output - yours may be different.
0

cd /etc/network/if-up.d && iptables-save > firewall.conf && echo -e '#!/bin/sh -e\niptables-restore < $(dirname $0)/firewall.conf' > iptables && chmod a+x iptables

pkufranky · 2011-05-01 03:23:26 3
Create cheap and easy index.html file

Just to avoid link to itself
This is sample output - yours may be different.
0

F=index.html; for i in *; do [[ $i = $F ]] && continue; echo "<li><a href='$i'>$i</a>"; done >$F

frans · 2011-05-08 20:57:24 5
Display GCC Predefined Macros

another one
This is sample output - yours may be different.
0

echo | gcc -dM -E -

Byung · 2011-05-09 09:59:24 3
Show seconds since modified of newest modified file in directory
This is sample output - yours may be different.
0

FILE=`ls -ltr /var/lib/pgsql/backups/daily/ | tail -n1 | awk '{print $NF}'`; TIME=`stat -c %Y /var/lib/pgsql/backups/daily/$FILE`; NOW=`date +%s`; echo $((NOW-TIME))

allrightname · 2011-05-12 13:21:37 6
log rm commands

Sometimes, it is annoying to find your files or directories missing. If you want to log all the rm commands you can put this in /etc/profile.
This is sample output - yours may be different.
0

function rm { workingdir=$( pwdx $$ | awk '{print $2}' ) /usr/bin/rm $* echo "rm $* issued at $(date) by the user $(who am i| awk '{print $1} ') in the directory ${workingdir}" >> /tmp/rm.out }

soulonfire · 2011-06-22 14:47:38 21
Create a temp file

Another way to create temp files in your scripts, if tempfile fails, it will create a hidden local file in the current directory, don't forget to delete $FILE
This is sample output - yours may be different.
0

FILE=$(tempfile 2>/dev/null || echo .$RANDOM)

h3nr1x · 2011-06-22 15:12:21 3
Check if commands are available on your system
This is sample output - yours may be different.
0

for c in gcc bison dialog bc asdf; do if ! which $c >/dev/null; then echo Required program $c is missing ; exit 1; fi; done

Mozai · 2011-06-27 12:54:02 3
Discover unoptimized MySQL tables and optimize them.

Finds all tables that need optimising and loops through them, running optimise against them. This works server-wide, on all databases and tables.
This is sample output - yours may be different.
0

for table in $(echo "select concat(TABLE_SCHEMA, '.', TABLE_NAME) from information_schema.TABLES where TABLE_SCHEMA NOT IN ('information_schema','mysql') and Data_free > 0" | mysql --skip-column-names); do echo "optimize table ${table}" | mysql; done;

Xiol · 2011-06-28 21:09:57 4
print an 'hello world'
This is sample output - yours may be different.
0

echo 'hello world'

aykut · 2011-07-06 17:54:47 3
Find .java files with high complexity (counting curly braces)
This is sample output - yours may be different.
0

find src/ -name "*.java" | while read f; do echo -n "$f "; cat "$f" | tr -dc '{}'; echo; done | awk '{ print length($2), $1 }' | sort -n

mindsocket · 2011-07-21 01:25:31 8
split a string (2)
This is sample output - yours may be different.
0

read VAR1 VAR2 VAR3 <<< aa bb cc; echo $VAR2

h3xx · 2011-07-24 18:56:30 3
Create a QR code image in MECARD format

If your contact information was entered when your user account was created (it gets added to /etc/passwd) then this gets that info and creates a QR code for you automatically
This is sample output - yours may be different.
0

getent passwd $(whoami) | echo "$(perl -ne '/^([^:]+):[^:]+:[^:]+:[^:]+:([^ ]+) ?([^,]+)?,([^,]*),([^,]*),([^:,]*),?([^:,]*)/ and printf "MECARD:N:$3,$2;ADR:$5;TEL:$4;TEL:$6;EMAIL:$1@"')$HOSTNAME;;" | qrencode -o myqr.png

Strawp · 2011-07-25 12:59:57 3
progress bar for cp

Cleaner, but probably less portable. Works with bash4 and should also work on bash3. IIRC, $(()) and (()) are bashisms, not POSIX. Show Sample Output
This is sample output - yours may be different.
```
[========================================================>.............] 81%
```
0

while [$((or_sz=$(stat -c %s "$1"))) -gt $((ds_sz=$(stat -c %s "$2")))];do ((pct=(69*$ds_sz)/$or_sz));echo -en "\r[";for ((i=1;i<=pct;i++));do echo -n "=";done;echo -n \>;for ((i=pct;i<=68;i++));do echo -n ".";done;echo -n "] $(((100*$pct)/69))%";done

ScriptFanix · 2011-07-29 17:41:56 3
See how many more processes are allowed, awesome!
This is sample output - yours may be different.
0

echo $(($(ulimit -u)-$(pgrep -u $USER|wc -l))

h3xx · 2011-07-30 05:03:36 3
Grep across a directory and open matching files in vim (one tab per file)

vim 7 required
This is sample output - yours may be different.
0

vim -p `grep -r PATTERN TARGET_DIR | cut -f1 -d: | sort | uniq | xargs echo -n`

kovagoz · 2011-08-05 16:34:31 4
Check if your webserver supports gzip compression with curl
This is sample output - yours may be different.
0

if curl -s -I -H "Accept-Encoding: gzip,deflate" http://example.com/ | grep 'Content-Encoding: gzip' >/dev/null 2>&1 ; then echo Yes; else echo No;fi

rwky · 2011-08-16 21:48:14 3
Sum size of files returned from FIND

Just an alternative. Here the output of the subshell statement is a complete script for dc so you can save it, manipulate it with some other tool or just debug it with less.
This is sample output - yours may be different.
0

(echo 0; find [args...] -printf '%s +\n'; echo p) | dc

wipu · 2011-08-17 07:49:55 4
Print repeating CSV values on new lines - normalize repeating fields

Lets say you have a file with the following layout: LINUX,DIR,FILE1,FILE2,FILE3 You want the file to look like this: LINUX,DIR,FILE1 LINUX,DIR,FILE2 LINUX,DIR,FILE3 This perl command does it for you. Show Sample Output
This is sample output - yours may be different.
```
LINUX,DIR,FILE1
LINUX,DIR,FILE2
LINUX,DIR,FILE3
```
0

echo "LINUX,DIR,FILE1,FILE2,FILE3" | perl -aF, -nle 'my ($fld1, $fld2, @fields) = @F; while(@fields) { print join ",", $fld1, $fld2, splice(@fields, 0, 1) }'

mindrape · 2011-08-22 18:27:12 4
Pipe stdout to image and mail

sudo /sbin/ifconfig | gotxt2imgmail you@example.com
This is sample output - yours may be different.
0

gotxt2imgmail() { if [ $# != 1 ]; then echo 'gotxt2imgmail < email >'; return; fi; e="$1"; f=$RANDOM.png; convert label:@- $f; echo "" | mailx -s $f -a $f $e }

meathive · 2011-08-24 12:05:05 3
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Clear filesystem memory cache

Found here: http://ubuntuforums.org/showthread.php?t=589975

fetch all revisions of a specific file in an SVN repository

Manages everything through one sed script instead of pipes of greps and awks. Quoting of shell variables is generally easier within a sed script.

Count lines of source code excluding blank lines and comments

Much more accurate than other methods mentioned here straight out of the box.

Get own public IP address

Plain Text Ip Output, independent of Layout change.

Find the real procesor speed when you use CPU scaling [cpuspeed]

We don't use CPU scaling, but just in case you do, there is something interesting to note. If you look at the /proc/cpuinfo, the speed listed is current running speed of the processors and not the real speed of the chip.

Download Apple movie trailers

Copy the link to an HD movie trailer in to this command. It's more eleganant if it's put in a to a script, taking the URL as input.

Create a file of a given size in linux

If you're trying to create a sparse file, you can use dd by 'skip'ing to the last block instance. ls -ls shows the actual size vs. the reported size

host - DNS lookup utility

host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command line arguments and options.

Adequately order the page numbers to print a booklet

Useful if you don't have at hand the ability to automatically create a booklet, but still want to. F is the number of pages to print. It *must* be a multiple of 4; append extra blank pages if needed. In evince, these are the steps to print it, adapted from https://help.gnome.org/users/evince/stable/duplex-npage.html.en : 1) Click File ▸ Print. 2) Choose the General tab. Under Range, choose Pages. Type the numbers of the pages in this order (this is what this one-liner does for you): n, 1, 2, n-1, n-2, 3, 4, n-3, n-4, 5, 6, n-5, n-6, 7, 8, n-7, n-8, 9, 10, n-9, n-10, 11, 12, n-11... ...until you have typed n-number of pages. 3) Choose the Page Setup tab. - Assuming a duplex printer: Under Layout, in the Two-side menu, select Short Edge (Flip). - If you can only print on one side, you have to print twice, one for the odd pages and one for the even pages. In the Pages per side option, select 2. In the Page ordering menu, select Left to right. 4) Click Print.

use the real 'rm', distribution brain-damage notwithstanding

The backslash avoids any 'rm' alias that might be present and runs the 'rm' command in $PATH instead. In a misguided attempt to be more "friendly", some Linux distributions (or sites/etc.) alias 'rm' to 'rm -i'. Unfortunately, this trains users to expect that files won't actually be deleted until they okay it. This expectation will fail with catastrophic results when they use other distributions, move to other sites, etc., and doesn't really even work 100% even with the alias. It's too late to fix 'rm', but '\rm' should work everywhere (under bash).

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Commands using echo (1,545)

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