Commands using printf (206)
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Converts a number of bytes provided as input, to a human readable number. Show Sample Output
2human_filesize() { awk -v sum="$1" ' BEGIN {hum[1024^3]="Gb"; hum[1024^2]="Mb"; hum[1024]="Kb"; for (x=1024^3; x>=1024; x/=1024) { if (sum>=x) { printf "%.2f %s\n",sum/x,hum[x]; break; } } if (sum<1024) print "1kb"; } '} -
Unlike other alternatives, this command only relies on bash builtins and should also work on windows platforms with the bash executable. Sparseness corresponds to the number 128 and can be adjusted. To print all possible digits instead of only 0 and 1 replace RANDOM%2 by RANDOM%10 or RANDOM%16 to add letters [A-F]. Show Sample Output
2while true; do printf "\e[32m%X\e[0m" $((RANDOM%2)); for ((i=0; i<$((RANDOM%128)); i++)) do printf " "; done; done -
2today() { printf '%(%Y-%m-%d)T\n' -1; } ## bash-4
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opposite of https://www.commandlinefu.com/commands/view/10014/urldecoding-with-one-pure-bash-builtin ;-) Show Sample Output
2function URLEncode { local dataLength="${#1}"; local index; for ((index = 0;index < dataLength;index++)); do local char="${1:index:1}"; case $char in [a-zA-Z0-9.~_-]) printf "$char"; ;; *) printf "%%%02X" "'$char"; ;; esac; done; } -
2printf '*%.s' {1..40}; echo
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No need to use perl, awk, nor /usr/bin/date -- bash's "printf" builtin will do it. Show Sample Output
2printf '%(%FT%T)T\n' 1606752450 -
Sometimes, in a shell script, you need a random number bigger than the range of $RANDOM. This will print a random number made of four hex values extracted from /dev/urandom. Show Sample Output
1printf %d 0x`dd if=/dev/urandom bs=1 count=4 2>/dev/null | od -x | awk 'NR==1 {print $2$3}'` -
1echo '123/7' |bc -l |xargs printf "%.3f\n"
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1printf "%d\n" "'A" "'B"
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printf treats first char after single ' as numeric equivalent
1ord() { printf "%d\n" "'$1"; } -
1printf "%s\n" .*
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Prompts the user for username and password, that are then exported to http_proxy for use by wget, yum etc Default user, webproxy and port are used. Using this script prevent the cleartext user and pass being in your bash_history and on-screen Show Sample Output
1set-proxy () { P=webproxy:1234; DU="fred"; read -p "username[$DU]:" USER; printf "%b"; UN=${USER:-$DU}; read -s -p "password:" PASS; printf "%b" "\n"; export http_proxy="http://${UN}:${PASS}@$P/"; export ftp_proxy="http://${UN}:${PASS}@$P/"; } -
This one uses hex conversion to do the converting and is in shell/sed only (should probably still use the python/perl version).
1uri_escape(){ echo -E "$@" | sed 's/\\/\\\\/g;s/./&\n/g' | while read -r i; do echo $i | grep -q '[a-zA-Z0-9/.:?&=]' && echo -n "$i" || printf %%%x \'"$i" done } -
underline() will print $1, followed by a series of '=' characters the width of $1. An optional second argument can be used to replace '=' with a given character. This function is useful for breaking lots of data emitted in a for loop into sections which are easier to parse visually. Let's say that 'xxxx' is a very common pattern occurring in a group of CSV files. You could run
grep xxxx *.csvThis would print the name of each csv file before each matching line, but the output would be hard to parse visually.for i in *.csv; do printf "\n"; underline $i; grep "xxxx" $i; doneWill break the output into sections separated by the name of the file, underlined. Show Sample Output1underline() { echo $1; for (( i=0; $i<${#1}; i=$i+1)); do printf "${2:-=}"; done; printf "\n"; } -
The function 'box' takes either one or two arguments. The first argument is a line of text to be boxed, the second argument (optional) is a character to use to draw the box. By default, the drawing character will be '='. The function 'n()' is a helper function used to draw the upper and lower lines of the box, its arguments are a length, and an character to print. (I used 'n' because 'line', 'ln' and 'l' are all commonly used) Show Sample Output
1box() { l=${#1}+4;x=${2:-=};n $l $x; echo "$x $1 $x"; n $l $x; }; n() { for (( i=0; $i<$1; i=$i+1)); do printf $2; done; printf "\n"; } -
1pmap $(pgrep [ProcessName] -n) | gawk '/total/ { a=strtonum($2); b=int(a/1024); printf b};'
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This one liner; combines all sequentially numbered files; in this example IMG_0001.png to IMG_1121.png by generating the shell script, making the shell script executable and then running the shell script to combine the 1121 png into a single png file named _final.png tested on Mac OS X 10.6.3 with ImageMagick 6.5.8-0 2009-11-22 Q16 http://www.imagemagick.org
1echo -n "convert " > itcombino.sh; printf "IMG_%00004u.png " {1..1121} >> itcombino.sh; echo -n "-layers merge _final.png" >> itcombino.sh; chmod +x itcombino.sh && ./itcombino.sh -
The first argument is the interpreter for your script, the second argument is the name of the script to create. Show Sample Output
1shebang() { if i=$(which $1); then printf '#!%s\n\n' $i > $2 && vim + $2 && chmod 755 $2; else echo "'which' could not find $1, is it in your \$PATH?"; fi; } -
A shorter version Show Sample Output
1while cat /proc/net/dev; do sleep 1; done | awk '/eth0/ {o1=n1; o2=n2; n1=$2; n2=$10; printf "in: %9.2f\t\tout: %9.2f\r", (n1-o1)/1024, (n2-o2)/1024}' -
Watch the temperatures of your CPU cores in real time at the command line. Press CONTROL+C to end. GORY DETAILS: Your computer needs to support sensors (many laptops, for example, do not). You'll need to install the lm-sensors package if it isn't already installed. And it helps to run the `sensors-detect` command to set up your sensor kernel modules first. At the very end of the sensors-detect interactive shell prompt, answer YES to add the new lines to the list of kernel modules loaded at boot. Show Sample Output
1while :; do sensors|grep ^Core|while read x; do printf '% .23s\n' "$x"; done; sleep 1 && clear; done; -
Replace service --status-all 2>&1 by service --status-all 2>/dev/null to hide all services with the status [ ? ]
1services() { printf "$(service --status-all 2>&1|sed -e 's/\[ + \]/\\E\[42m\[ + \]\\E\[0m/g' -e 's/\[ - \]/\\E\[41m\[ - \]\\E\[0m/g' -e 's/\[ ? \]/\\E\[43m\[ ? \]\\E\[0m/g')\n";} -
1arp-scan -I eth0 -l | perl -ne '/((\d{1,3}\.){3}\d{1,3})/ and $ip=$1 and $_=`nmblookup -A $ip` and /([[:alnum:]-]+)\s+<00>[^<]+<ACTIVE>/m and printf "%15s %s\n",$ip,$1'
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Check the API. You shouldn't need sed. The print-newline at the end is to prevent zsh from inserting a % after the end-of-output. Also works with http://v.gd Show Sample Output
1isgd () { curl 'http://is.gd/create.php?format=simple&url='"$1" ; printf "\n" } -
This one line Perl script will display the smallest to the largest files sizes in all directories on a server. Show Sample Output
1du -k | sort -n | perl -ne 'if ( /^(\d+)\s+(.*$)/){$l=log($1+.1);$m=int($l/log(1024)); printf ("%6.1f\t%s\t%25s %s\n",($1/(2**(10*$m))),(("K","M","G","T","P")[$m]),"*"x (1.5*$l),$2);}' | more -
Counts the files present in the different directories recursively. One only has to change maxdepth to have further insight in the directory hierarchy. Found at unix.stackexchange.com: http://unix.stackexchange.com/questions/4105/how-do-i-count-all-the-files-recursively-through-directories Show Sample Output
1find -maxdepth 3 -type d | while read -r dir; do printf "%s:\t" "$dir"; find "$dir" | wc -l; done - ‹ First < 2 3 4 5 6 > Last ›
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