Commands using test sorted by votes

Commands using test (35)

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Find broken symlinks

Locate broken symlinks in the current directory. Also useful, to remove broken links: find . -type l ! -exec test -e {} \; -print0 | xargs -0 rm
This is sample output - yours may be different.
13

find . -type l ! -exec test -e {} \; -print

Shango1980 · 2009-02-18 15:34:25 24
Show Directories in the PATH Which does NOT Exist

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
This is sample output - yours may be different.
9

(IFS=:;for p in $PATH; do test -d $p || echo $p; done)

haivu · 2009-09-19 17:51:06 9
Find files containing string and open in vim

I often use "vim -p" to open in tabs rather than buffers.
This is sample output - yours may be different.
4

vim $(grep test *)

goatboy · 2009-07-15 10:15:04 4
for all who don't have the watch command

#Usage: watch timeinsecond "command" Show Sample Output
This is sample output - yours may be different.
```
Every 3s: ls 				 Mi 19 Aug 2009 17:27:24 CEST
file1
file2
file3
...
```
4

watch() { while test :; do clear; date=$(date); echo -e "Every "$1"s: $2 \t\t\t\t $date"; $2; sleep $1; done }

peshay · 2009-08-19 15:29:00 3
I finally found out how to use notify-send with at or cron

The simplest way to do it. Works for me, at least. (Why are the variables being set?)
This is sample output - yours may be different.
4

echo notify-send test | at now+1minute

polar · 2010-08-08 03:11:11 8
Find broken symlinks and delete them

This command is adapted from http://otomaton.wordpress.com/2012/12/26/find-broken-symbolic-links/ Solutions with find -L don't work when the link is a loop, an error message is printed.
This is sample output - yours may be different.
4

find . -type l -exec test ! -e {} \; -delete

seb1245 · 2012-12-26 06:27:13 7
check for write/read permissions

su www-apache/ftp user and then check readable: find ~/ -type d $ -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' $ -prune -o -exec test -r {} \; -exec echo {} readable \; 2>/dev/null check writable: find ~/ -type d $ -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' $ -prune -o -exec test -w {} \; -exec echo {} writable \; 2>/dev/null
This is sample output - yours may be different.
4

find ~/ -type d $ -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' $ -prune -o -exec test -w {} \; -exec echo {} writable \; 2>/dev/null

cas_alexi · 2013-02-27 13:18:47 7
for all who don't have the watch command
This is sample output - yours may be different.
3

watch() { t=$1; shift; while test :; do clear; date=$(date); echo -e "Every "$t"s: $@ \t\t\t\t $date"; $@; sleep $t; done }

yaccovs · 2009-08-19 19:55:55 3
Is it a terminal?

Oddly, the isatty(3) glibc C call doesn't have a direct analogue as a command 'isatty(1)'. All is not lost as you can use test(1). For example, your script might be run from a tty or from a GUI menu item but it needs to get user-input or give feedback. Now your script can test STDIN with 'isatty 0' or STDOUT with 'isatty 1' and use xmessage(1) if the tty is not available. The other way to test for this is with 'tty -s' - but that's only for STDIN.
This is sample output - yours may be different.
3

isatty(){ test -t $1; }

bhepple · 2010-01-06 06:50:01 4
Re-emerge all ebuilds with missing files (Gentoo Linux)

Revised approach to and3k's version, using pipes and read rather than command substitution. This does not require fiddling with IFS when paths have whitespace, and does not risk hitting command-line size limits. It's less verbose on the missing files, but it stops iterating at the first file that's missing, so it should be definitely faster. I expanded all the qlist options to be more self-describing.
This is sample output - yours may be different.
3

emerge -av1 `qlist --installed --nocolor | uniq | while read cp; do qlist --exact $cp | while read file; do test -e $file || { echo $cp; echo "$cp: missing $file (and maybe more)" 1>&2; break; }; done; done`

Flameeyes · 2010-07-04 19:55:42 8
Get fully qualified domain names (FQDNs) for IP address with failure and multiple detection
This is sample output - yours may be different.
2

NAME=$(nslookup $IP | sed -n 's/.*arpa.*name = $.*$/\1/p'); test -z "$NAME" && NAME="NO_NAME"; echo "$NAME"

morlockhq · 2009-02-05 15:21:22 48
grep -v with multiple patterns.

You can use -e to pass multiple patterns.
This is sample output - yours may be different.
2

grep test somefile | grep -v -e error -e critical -e warning

pipping · 2009-10-24 15:58:11 3
View all file operator expressions for any file, test, stat

Applies each file operator using the built-in test. testt /home/askapache/.sq /home/askapache/.sq -a True - file exists. -d True - file is a directory. -e True - file exists. -r True - file is readable by you. -s True - file exists and is not empty. -w True - the file is writable by you. -x True - the file is executable by you. -O True - the file is effectively owned by you. -G True - the file is effectively owned by your group. -N True - the file has been modified since it was last read. Full Function: testt () { local dp; until [ -z "${1:-}" ]; do dp="$1"; [[ ! -a "$1" ]] && dp="$PWD/$dp"; command ls -w $((${COLUMNS:-80}-20)) -lA --color=tty -d "$dp"; [[ -d "$dp" ]] && find "$dp" -mount -depth -wholename "$dp" -printf '%.5m %10M %#15s %#9u %-9g %#5U %-5G %Am/%Ad/%AY %Cm/%Cd/%CY %Tm/%Td/%TY [%Y] %p\n' -a -quit 2> /dev/null; for f in a b c d e f g h L k p r s S t u w x O G N; do test -$f "$dp" && help test | sed "/-$f F/!d" | sed -e 's#^[\t ]*-$[a-zA-Z]\{1\}$ F[A-Z]*[\t ]* True if#-\1 "'$dp'" #g'; done; shift; done } Show Sample Output
This is sample output - yours may be different.
```
$ testt /dev/pts/3 
/dev/pts/3
-a True - file exists.
-c True - file is character special.
-e True - file exists.
-r True - file is readable by you.
-w True - the file is writable by you.
-N True - the file has been modified since it was last read.


$ testt /home/askapache/.sq
/home/askapache/.sq
-a True - file exists.
-d True - file is a directory.
-e True - file exists.
-r True - file is readable by you.
-s True - file exists and is not empty.
-w True - the file is writable by you.
-x True - the file is executable by you.
-O True - the file is effectively owned by you.
-G True - the file is effectively owned by your group.
-N True - the file has been modified since it was last read.
```
2

testt(){ o=abcdefghLkprsStuwxOGN;echo $@;for((i=0;i<${#o};i++));do c=${o:$i:1};test -$c $1 && help test | sed "/^ *-$c/!d;1q;s/^[^T]*/-$c /;s/ if/ -/";done; }

AskApache · 2012-02-21 16:54:53 11
Compare a remote file with a local file

This method does not transfer the contents of the entire file, instead it computes a md5 sum of the file on each end so that large files can be compared without transferring them across the net.
This is sample output - yours may be different.
1

test "$(md5sum /local/file | cut -d' ' -f1)" == "$(ssh root@xen -- md5sum /remote/file | cut -d' ' -f1)" && echo "Match" || echo "Differ"

gnif · 2015-04-24 03:09:33 11
Continuously listen on a port and respond with a fixed message with netcat (and respond to kill signals)

`while true`: do forever `nc -l -p 4300 -c 'echo hello'`: this is the but anything can go here really `test $? -gt 0 && break`: this checks the return code for ctrl^c or the like and quite the loop, otherwise in order to kill the loop you'd have to get the parent process id and kill it. Show Sample Output
This is sample output - yours may be different.
```
Terminal 1% while true ; do nc -l -p 4300 -c 'echo hello'; test $? -gt 0 && break; done

Terminal 2% echo hi | nc localhost 4300
hello
Terminal 2% echo hi | nc localhost 4300
hello

Terminal 1% ^C
Terminal 1%
```
1

while true ; do nc -l -p 4300 -c 'echo hello'; test $? -gt 0 && break; done

rawco · 2016-03-22 21:55:44 14
checks size of directory & delete it if its to small

only simple example how to combine rclone & jq Show Sample Output
This is sample output - yours may be different.
```
Transferred:              0 / 0 Byte, -, 0 Byte/s, ETA -
Errors:                 1 (retrying may help)   
Deleted:                0 (files), 3 (dirs)
Elapsed time:        14.2sTransferred:                    0 / 0 Byte, -, 0 Byte/s, ETA -
Errors:                 1 (retrying may help)
Deleted:                0 (files), 3 (dirs)
Elapsed time:        14.2s
2021/07/25 11:14:04 Failed to purge: unlinkat /mnt/anime/Anime/Fansub/Basquash! (2009): input/output error
```
1

for i in *; do test -d "$i" && ( rclone size "$i" --json -L 2> /dev/null | jq --arg path "$i" 'if .bytes < 57462360 then ( { p: $path , b: .bytes}) else "none" end' | grep -v none | jq -r '.p' | parallel -j3 rclone purge "{}" -v -P ); done

dbiesecke · 2021-07-25 09:16:03 352
Create a folder but first you can test if it exists
This is sample output - yours may be different.
0

test -d folder || mkdir folder

wilbercarmona · 2011-06-02 23:36:32 4
find broken symbolic links

find broken symbolic links Show Sample Output
This is sample output - yours may be different.
```
lrwxrwxrwx 1 nobody nobody 43 2010-03-15 13:00 /mnt/retorn -> /opt/retorn
```
0

find . -type l | (while read FN ; do test -e "$FN" || ls -ld "$FN"; done)

pathcl · 2011-08-02 14:48:47 6
Check variable has been set

Got the idea from there http://fixunix.com/questions/15902-bash-checking-if-env-var-set.html Show Sample Output
This is sample output - yours may be different.
```
$ isdef a_var; echo $?
1
$ a_var=1
$ isdef a_var; echo $?
0
```
0

isdef() { eval test -n \"\${$1+1}\"; }

keymon · 2011-09-29 15:39:51 4
for all who don't have the watch command

allows command to use switches
This is sample output - yours may be different.
0

watch() { if [ -z "$1" ]; then echo "usage: watch interval command" return fi sec=$1 shift while test :; do clear; date=$(date); echo -e "Every "$sec"s: $@ \t\t\t\t $date"; echo $@; sleep $sec; done }

kneufeld · 2012-02-29 17:10:19 4
Change owner ship of files from 1003 to android under current directory recursively. 1003/android could be customized.
This is sample output - yours may be different.
0

find . | while read line; do test `stat -c %u $line` -eq 1003 && chown android:android $line && echo $line; done

changyuheng · 2013-01-12 10:47:25 8
Create a new detached screen session running command in background

The command creates new session "test", executes 'date' and then start your default shell (to keep the detached session alive). Change 'date' to fit your needs. screen -r test will attach the created session.
This is sample output - yours may be different.
0

$ screen -S test -d -m -- sh -c 'date; exec $SHELL'

awek · 2014-02-17 08:11:45 8
Recursive find all mp4s in a folder and convert to ogv if the ogv does not exist or the mp4 is newer then the current ogv
This is sample output - yours may be different.
0

for file in $(find . -name *.mp4); do ogv=${file%%.mp4}.ogv; if test "$file" -nt "$ogv"; then echo $file' is newer then '$ogv; ffmpeg2theora $file; fi done

fatlinesofcode · 2014-04-14 23:26:19 7
Print out which hosts are not running specific process

Given a hosts list, ssh one by one and echo its name only if 'processname' is not running. Show Sample Output
This is sample output - yours may be different.
```
hostone
hosttwo
hostthree
```
0

for i in `cat hosts_list`; do RES=`ssh myusername@${i} "ps -ef " |awk '/[p]rocessname/ {print $2}'`; test "x${RES}" = "x" && echo $i; done

arlequin · 2014-10-03 14:57:54 9
Turn monitor on or off if off or on, respectively

that's how I do it in ubuntu
This is sample output - yours may be different.
0

echo test $DISPLAY > /dev/null || export DISPLAY=:0.0; xset dpms force off;gnome-screensaver-command -l

gargolito · 2015-04-07 19:12:45 9
1 2 >

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dd with progress bar and statistics

This command utilizes 'pv' to show dd's progress. Notes on use with dd: -- dd block size (bs=...) is a widely debated command-line switch and should usually be between 1024 and 4096. You won't see much performance improvements beyond 4096, but regardless of the block size, dd will transfer every bit of data. -- pv's switch, '-s' should be as close to the size of the data source as possible. -- dd's out file, 'of=...' can be anything as the data within that file are the same regardless of the filename / extension.

Quick HTML image gallery

My take on the original: even though I like the other's use of -exec echo, sed just feels more natural. This should also be slightly easier to improve. I expanded this into a script as an exercise, which took about 35 minutes (had to look up some docs): http://bitbucket.org/kniht/nonsense/src/7c1b46488dfc/commandlinefu/quick_image_gallery.py

Run a command as root, with a delay

$ sleep 1h ; sudo command or $ sudo sleep 1h ; sudo command won't work, because by the time the delay is up, sudo will want your password again.

Notepad in a browser

A commandline version of the notepad in a browser: http://www.commandlinefu.com/commands/view/12161/notepad-in-a-browser-type-this-in-the-url-bar All credit to the origional author of this fantastic command, whos only failing as most of the comments pointed out was that it wasn't a command... well, now its a command. Send all upvotes to dtlp747.

Show a line when a "column" matchs

count of down available ips

Query Wikipedia via console over DNS

Remove a line from a file using sed (useful for updating known SSH server keys when they change)

For example, to remove line 5 from foo, type: vi +5d +wq foo

Force machine to reboot no matter what (even if /sbin/shutdown is hanging)

This will cause your machine to INSTANTLY reboot. No un-mounting of drives or anything. Very handy when something has gone horribly wrong with your server in that co-location facility miles away with no remote hands! Suspect this works with all 2.2, 2.4 and 2.6 Linux kernels compiled with magic-syskey-request support.

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

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Commands using test (35)

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