Commands using printf (206)

  • Uses soxi instead of mplayer


    0
    soxi -D * | awk '{SUM += $1} END { printf "%d:%d:%d\n",SUM/3600,SUM%3600/60,SUM%60}'
    hufman · 2017-04-08 17:37:03 15
  • All the other example fail when running in a folder containing too many files due to * being saturated. This command does not use *, allowing me to run it in one folder containing over 300000 audio files. As to running on so many files, I used GNU parallel in order to spawn as many processes as cores, tremendously fasting up the process. Show Sample Output


    0
    ls|grep ".wav"|parallel -j$(nproc) soxi -D {}|awk '{SUM += $1} END { printf "%d:%d:%d\n",SUM/3600,SUM%3600/60,SUM%60}'
    jupiter126 · 2017-05-02 21:37:24 20
  • Prints the variable "$a" 80 times with a new line at the end. There is no need for backspaces as printf (by default) does not print a newline nor an space. Use a bunch of variables called "$_0" and a number. The name start with an underscore and a 0 to avoid conflicts with already defined variables. If still worried: All variables may be cleared up before use with "unset $_{1..080}". A command with a variable count is a bit of a mouthful: a=hello+; n=7; eval printf "%s" '$_{1..0'"$n"'}"$a"' $'$\'\\n\'' And carry some risk if the variable "$n" could be set by an attacker. Show Sample Output


    0
    a=+; printf "%s" $_{1..080}"$a" $'\n'
    isaacmarcos · 2017-06-06 21:59:58 17
  • This is a bit of a bash hack to catch STDERR and append a log level to it. So for example, if your script has pseudo loglevels like so: echo "INFO - finding files" [ -f ${files} ] || echo "WARN - no files found" Any subcommands that write to STDERR will screw that up Adding 2> >(fb=$(dd bs=1 count=1 2>/dev/null | od -t o1 -A n); [ "$fb" ] && err=$(printf "\\${fb# }"; cat) && echo "ERROR - $err") to the command does the following: 2> Redirect STDERR >( Spawn a subshell (STDERR is then redirected to the file descriptor for this subshell) fb=$(....) get the first byte of input [ "$fb" ] test if there's a first byte && err=$(printf....) save the output to the $err variable && echo "ERROR - $err" append your pseudo loglevel and the error message Heavily borrowed from https://unix.stackexchange.com/questions/33049/check-if-pipe-is-empty-and-run-a-command-on-the-data-if-it-isnt Show Sample Output


    0
    [command] 2> >(fb=$(dd bs=1 count=1 2>/dev/null | od -t o1 -A n); [ "$fb" ] && err=$(printf "\\${fb# }"; cat) && echo "ERROR - $err")
    tyzbit · 2017-10-16 22:22:42 21
  • Compactly display a bitcoin-cli fee estimate in satoshis/Byte, sat/B, date time stamp. Change the 6 to the desired number of confirmations. Display in btc/KB unit of measure: printf %g "$(bccli estimatesmartfee 6 "ECONOMICAL" | jq .feerate)";printf " btc/KB estimated feerate for 6 confirmations\nMultiply by 100,000 to get sat/B\n"; Two settings for estimate mode are "ECONOMICAL". "CONSERVATIVE" is the same as "UNSET" # jq is a json filter. sudo apt-get install jq Show Sample Output


    0
    printf %g "$(bitcoin-cli estimatesmartfee 6 "ECONOMICAL" | jq .feerate*100000)";printf " sat/B estimated feerate for 6 confirmations as of $(date +%c)\nDivide by 100,000 to get btc/KB\n"
    deinerson1 · 2018-06-20 13:40:32 240
  • Use this function with bash version 4+ to convert arbitrary hexadecimal sequences to binary. If you don't have bash 4+ then modify the lowercase to uppercase demangling statement s=${@^^} to set s equal to the uppercase hex input or the bc command throws an input parser error. Show Sample Output


    0
    hex2bin () { s=${@^^}; for i in $(seq 0 1 $((${#s}-1))); do printf "%04s" `printf "ibase=16; obase=2; ${s:$i:1};\n" | bc` ; done; printf "\n"; }
    RiskNerd · 2018-10-02 22:02:33 350

  • 0
    printf %s\\n '"\en": "\e0\e."' '"\em": "\e1\e."' '"\e,": "\e2\e."'>>~/.inputrc
    lri · 2019-01-22 07:10:16 32
  • This shell calculator uses POSIX features only and is therefore portable. By default the number of significant figures is limited to 8 with trailing zeros stripped, resembling the display of a basic pocket calculator. You might want to increase this to 12 to emulate a scientific calculator. Show Sample Output


    0
    calc(){ printf "%.8g\n" $(printf "%s\n" "$*" | bc -l); }
    lordtoran · 2019-02-06 23:32:35 607
  • No need to fork off a process.


    0
    printf "%.s*" {1..40}; printf "\n"
    doododoltala · 2019-07-11 00:27:20 37
  • This “sysload” alias converts the load average to percentages and divides them by the number of CPUs/cores. It may provide a more intuitive guesstimate of how much work the server is doing. Show Sample Output


    0
    alias sysload='printf "System load (1m/5m/15m): "; for l in 1 2 3 ; do printf "%.1f%s" "$(( $(cat /proc/loadavg | cut -f $l -d " ") * 100 / $(nproc) ))" "% "; done; printf "\n"'
    lordtoran · 2021-03-27 17:10:53 150
  • Show temp of all disk with the drivetemp module activate Show Sample Output


    0
    grep -l "drivetemp" /sys/class/hwmon/hwmon*/name | while read f; do printf "%s(%-.2s°C)\n" "`<${f%/*}/device/model`" "`<${f%/*}/temp1_input`"; done
    kokoparkletal · 2023-09-10 18:24:29 80
  • This command adds the numbers 10, 12, 14 to a bunch of mp3's in the current working directory. You can then run the command replacing the inital i=10 with i=11 to add 11,13,15 in another directory then mv the files together and the first files interweave with the second group of files. I used this to weave a backlog of a podcast with other podcast so I didn't get sick of one while I was catching up. I started at 10 because printf blows up with 0 padded numbers 08 and 09 which kind of makes the printf command redundant as it was used to pad numbers 1 - 9 so they would come first and not get sorted incorrectly


    -1
    i=10;for o in *.mp3; do i=$(printf "%02d" $i); mv $o $i$o; ((i = $i + 2)); done
    bazzawill · 2009-04-13 12:33:52 7
  • There's no need for ls or grep; printf is builtin to most modern shells


    -1
    printf "%s\n" !(pattern) ## ksh, or bash with shopt -s extglob
    cfajohnson · 2009-11-26 14:09:56 3
  • So your boss wants to know how much memory has been assigned to each virtual machine running on your server... here's how to nab that information from the command line while logged in to that server Show Sample Output


    -1
    for file in $( vmrun list | grep 'vmx$' | sort ); do printf "% 40s %s M\n" $(echo "$( echo -n ${file}:\ ; grep memsize $file )" | sed -e 's/.*\///' -e 's/"//g' -e 's/memsize.=//'); done;
    linuxrawkstar · 2010-11-19 06:14:11 3
  • remove all carriage return of a given file (or input, if used with | ) and replace them with a space (or whatever character is after %s) Show Sample Output


    -1
    awk ' { printf ("%s ", $0)} END {printf ("\n") } ' FILE
    bouktin · 2011-02-02 11:51:41 6
  • The exported TSV file of Google Adwords' first five columns are text, they usually should collapse into one cell, a multi-line text cell, but there is no guaranteed way to represent line-break within cells for .tsv file format, thus Google split it to 5 columns. The problem is, with 5 columns of text, there are hardly space to put additional fields while maintain printable output. This script collapses the first five columns of each row into one single multi-line text cell, for console output or direct send to printer.


    -1
    awk -F $'\t' '{printf $1 LS $2 LS $3 LS $4 LS $5; for (i = 7; i < NF; i++) printf $i "\t"; printf "\n--\n";}' LS=$'\n' 'Ad report.tsv' | column -t -s $'\t'
    zhangweiwu · 2011-02-28 10:52:16 4
  • This command will delete all branches in your git repository other than next and master. I use this to cleanup my git repos after making multiple branches and merging them back into next. It's much faster than individually deleting each expired branch using: git branch -D <branch_name>


    -1
    git branch -D `git branch | awk '{ if ($0 !~ /next|master/) printf "%s", $0 }'`
    denheck · 2011-04-14 17:43:21 4
  • Group membership in OS X is a mish-mash of standards that end up meaning there's almost a half-dozen of ways to belong to a group, what with group inheritance and automatic assignment. This means there's no easy command to find out all groups a user belongs to. The only sensible way then is to list all users and then query each user for membership. NOTE: This is a function. Once input you can execute it by calling with a groupname. Show Sample Output


    -1
    members () { dscl . -list /Users | while read user; do printf "$user "; dsmemberutil checkmembership -U "$user" -G "$*"; done | grep "is a member" | cut -d " " -f 1; };
    eduo · 2012-05-20 11:34:33 7
  • I don't think it's possible to give a (background) colour to the tab itself, since a tab is, IIUC, simply a command to the terminal to move to the right. Nevertheless, this "highlighting" can be helpful when working with tab-separated files. Show Sample Output


    -1
    hl-nonprinting () { local C=$(printf '\033[0;36m') R=$(printf '\033[0m'); sed -e "s/\t/${C}&#9657;&$R/g" -e "s/$/${C}&#8267;$R/";}
    unhammer · 2012-11-07 09:55:48 4
  • Can't see it here, but the non-breaking space is highlighted :) Of course, cat -t -e achieves something similar, but less colourful. Could add more code points from https://en.wikipedia.org/wiki/Space_%28punctuation%29#Spaces_in_Unicode Show Sample Output


    -1
    hl-nonprinting () { local C=$(printf '\033[0;36m') B=$(printf '\033[0;46m') R=$(printf '\033[0m') np=$(env printf "\u00A0\uFEFF"); sed -e "s/\t/${C}&#9657;&$R/g" -e "s/$/${C}&#8267;$R/" -e "s/[$np]/${B}& $R/g";}
    unhammer · 2012-11-07 10:09:40 9

  • -1
    yes 'c=(" " " " " " 0 1); printf "${c[RANDOM%5]}"' | bash
    stx · 2013-11-09 16:10:41 6
  • Needs to be run in a battery sysfs dir, eg. /sys/class/power_supply/BAT0 on my system. Displays the battery's current charge and the rate per-second at which energy is {dis,}charging. All values are displayed as percentages of "full" charge. The first column is the current charge. The second is the rate of change averaged over the entire lifetime of the command (or since the AC cable was {un,}plugged), and the third column is the rate of change averaged over the last minute (controlled by the C=60 variable passed to awk). The sample output captures a scenario where I ran 'yes' in another terminal to max out a CPU. My battery was at 76% charge and you can see the energy drain starts to rise above 0.01% per-second as the cpu starts working and the fan kicks in etc. While idle it was more like 0.005% per-second. I tried to use this to estimate the remaining battery life/time until fully charged, but found it to be pretty useless... As my battery gets more charged it starts to charge slower, which meant the estimate was always wrong. Not sure if that's common for batteries or not. Show Sample Output


    -1
    while cat energy_now; do sleep 1; done |awk -v F=$(cat energy_full) -v C=60 'NR==1{P=B=$1;p=100/F} {d=$1-P; if(d!=0&&d*D<=0){D=d;n=1;A[0]=B=P}; if(n>0){r=g=($1-B)/n;if(n>C){r=($1-A[n%C])/C}}; A[n++%C]=P=$1; printf "%3d %+09.5f %+09.5f\n", p*$1, p*g, p*r}'
    sqweek · 2015-09-19 15:45:40 11
  • Better -and faster- using bash printf. Show Sample Output


    -2
    printf "%50s\n"|tr ' ' -
    rodolfoap · 2010-01-07 08:49:46 6

  • -2
    printf "%d\n" \0x64
    4Aiur · 2010-01-09 02:50:50 3

  • -2
    printf "%.50d" 0 | tr 0 -
    sata · 2010-03-25 12:52:45 3
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Search recursively to find a word or phrase in certain file types, such as C code
I have a bash alias for this command line and find it useful for searching C code for error messages. The -H tells grep to print the filename. you can omit the -i to match the case exactly or keep the -i for case-insensitive matching. This find command find all .c and .h files

List your installed Chromium extensions (with url to each page)
Gives you a list for all installed chrome (chromium) extensions with URL to the page of the extension. With this you can easy add a new Bookmark folder called "extensions" add every URL to that folder, so it will be synced and you can access the names from every computer you are logged in. ------------------------------------------------------------------------------------------------------------------ Only tested with chromium, for chrome you maybe have to change the find $PATH.

Convert Squid unixtime logs in human-readable ones
On-the-fly conversion of Unix Time to human-readable in Squid's access.log

Recursively remove all empty directories

Run a command multiple times with different subcommands
it's nice to be able to use the command `ls program.{h,c,cpp}`. This expands to `ls program.h program.c program.cpp`. Note: This is a text expansion, not a shell wildcard type expansion that looks at matching file names to calculate the expansion. More details at http://www.linuxjournal.com/content/bash-brace-expansion I often run multiple commands (like apt-get) one after the other with different subcommands. Just for fun this wraps the whole thing into a single line that uses brace expansion.

list block devices
Shows all block devices in a tree with descruptions of what they are.

sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)
POSIX requires this "string truncating" functionality. might as well use it, at least for very small tasks where invoking sed and using RE is overkill.

Silently ensures that a FS is mounted on the given mount point (checks if it's OK, otherwise unmount, create dir and mount)
In my example, the mount point is /media/mpdr1 and the FS is /dev/sdd1 /mountpoint-path = /media/mpdr1 filesystem=/dev/sdd1 Why this command ? Well, in fact, with some external devices I used to face some issues : during data transfer from the device to the internal drive, some errors occurred and the device was unmounted and remounted again in a different folder. In such situations, the command mountpoint gave a positive result even if the FS wasn't properly mounted, that's why I added the df part. And if the device is not properly mounted, the command tries to unmount, to create the folder (if it exists already it will also work) and finally mount the FS on the given mount point.

List all databases in Postgres and their (byte/human) sizes, ordering by byte size descending
Get a listing of all of your databases in Postgres and their sizes, ordering by the largest size first. Requires that you give the -d parameter a valid database name that you can connect to.

print a python-script (or any other code) with syntax-highlighting and no loss of indentation


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