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 $(date +%c)\nDivide by 100,000 to get btc/KB\n"
    deinerson1 · 2018-06-20 13:40:32 244
  • Use this function with bash version 4+ to convert arbitrary hexadecimal sequences to binary. If you don't have bash 4+ then modify the lowercase to uppercase demangling statement s=${@^^} 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 22:02:33 354

  • 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 17:10:53 154
  • 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 81
  • 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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print line and execute it in BASH
If script.sh contains only these two lines: $ uname -a $ whoami

Search files with js declarations inside
Useful to crawl where the javascript is declared, and extract it a common file. You can redirect it to a file to review item by item.

find process associated with a port
e.g. fuser 25/tcp (see which pid is listening on smtp)

Equivalent to ifconfig -a in HPUX

Create arbitrary big file full of zeroes but done in a second
If you want to create fast a very big file for testing purposes and you do not care about its content, then you can use this command to create a file of arbitrary size within less than a second. Content of file will be all zero bytes. The trick is that the content is just not written to the disk, instead the space for it is somehow reserved on operating system level and file system level. It would be filled when first accessed/written (not sure about the mechanism that lies below, but it makes the file creation super fast). Instead of '1G' as in the example, you could use other modifiers like 200K for kilobytes (1024 bytes), 500M for megabytes (1024 * 1024 bytes), 20G for Gigabytes (1024*1024*1024 bytes), 30T for Terabytes (1024^4 bytes). Also P for Penta, etc... Command tested under Linux.

Bitcoin Brainwallet Exponent Calculator
A bitcoin "brainwallet" is a secret passphrase you carry in your brain. The Bitcoin Brainwallet Exponent Calculator is one of three functions needed to calculate the bitcoin PRIVATE key. Roughly, the formula is exponent = sha256 (passphrase) Note that this is a bash function, which means you have to type its name to invoke it. You can check the accuracy of the results here http://brainwallet.org

See why a program can't seem to access a file
Sometimes a program refuses to read a file and you're not sure why. You may have display_errors turned off for PHP or something. In this example, fopen('/var/www/test/foo.txt') was called but doesn't have read access to foo.txt. Strace can tell you what went wrong. E.g., if php doesn't have read access to the file, strace will say "EACCESS (Permission denied)". Or, if the file path you gave doesn't exist, strace will say "ENOENT (No such file or directory)", etc. This works for any program you can run from the command-line, e.g., strace python myapp.py -e open,access... Note: the above command uses php-cli, not mod_php, which is a different SAPI with diff configs, etc.

open two files side by side in vim (one window, two panes)

postgresql SQL to show count of ALL tables (relations) including relation-size
Postgresql specific SQL - to show count of ALL tables including relation-size (pg_relation_size = used space on filesystem) - might need a VACUUM ANALYZE before showing all counts correctly !

Find default gateway


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