Commands tagged read (36)

  • minimal oneliner to keep track of time Show Sample Output


    0
    read year month day hour minutes seconds epoch _ < <(date '+%Y %m %d %H %M %S %s')
    snorf · 2015-11-11 07:27:37 0
  • The read command reads input and puts it into a variable. With -i you set an initial value. In this case I used a known environment variable. Show Sample Output


    3
    [ -n "$REMOTE_USER" ] || read -p "Remote User: " -er -i "$LOGNAME" REMOTE_USER
    pdxdoughnut · 2015-10-30 17:08:17 0
  • Reads n lines from stdin and puts the contents in a variable. Yes, I know the read command and its options, but find this logical even for one line. Show Sample Output


    -2
    VAR=$(head -5)
    rodolfoap · 2014-04-05 13:45:18 0
  • A bitcoin "brainwallet" is a secret passphrase you carry in the "wallet" of your brain. The Bitcoin Brainwallet Private Key Calculator calculates the standard base58 encoded bitcoin private key from your "brainwallet" passphrase. The private key is the most important bitcoin number. All other numbers can be derived from it. This command uses 3 other functions - all 3 are defined on my user page: 1) brainwallet_exponent() - search for Bitcoin Brainwallet Exponent Calculator 2) brainwallet_checksum() - search for Bitcoin Brainwallet Exponent Calculator 3) b58encode() - search for Bitcoin Brainwallet Base58 Encoder Do make sure you use really strong, unpredictable passphrases (30+ characters)! http:brainwallet.org can be used to check the accuracy of this calculator. Show Sample Output


    5
    (read -r passphrase; b58encode 80$( brainwallet_exponent "$passphrase" )$( brainwallet_checksum "$passphrase" ))
    nixnax · 2014-02-18 02:50:09 0
  • A bitcoin "brainwallet" is a secret passphrase you carry in your brain. The Bitcoin Brainwallet Private Key Base58 Encoder is the third of three functions needed to calculate a bitcoin PRIVATE key from your "brainwallet" passphrase. This base58 encoder uses the obase parameter of the amazing bc utility to convert from ASCII-hex to base58. Tech note: bc inserts line continuation backslashes, but the "read s" command automatically strips them out. I hope that one day base58 will, like base64, be added to the amazing openssl utility. Show Sample Output


    6
    function b58encode () { local b58_lookup_table=({1..9} {A..H} {J..N} {P..Z} {a..k} {m..z}); bc<<<"obase=58;ibase=16;${1^^}"|(read -a s; for b58_index in "${s[@]}" ; do printf %s ${b58_lookup_table[ 10#"$b58_index" ]}; done); }
    nixnax · 2014-02-18 02:29:30 0
  • Usage exaple cmd echo 'Sure to continue ??'; read -n1 choi; if [ "$choi" = 'y' ] || [ "$choi" = 'Y' ]; then echo -e '\nExecuting..'; else echo 'Aborted'; fi Show Sample Output


    6
    read -N1
    totti · 2013-10-10 10:09:43 1
  • Bash only, no sed, no awk. Multiple spaces/tabs if exists INSIDE the line will be preserved. Empty lines stay intact, except they will be cleaned from spaces and tabs if any available.


    5
    while read l; do echo -e "$l"; done <1.txt >2.txt
    knoppix5 · 2012-03-13 14:27:49 0
  • Very useful for test a script. After launch this command, you only have to press ENTER for launch your script again. I work with screen and tape ENTER instead of '!!'+ENTER If you break your script with CTRL-C, it will wait for press ENTER and will re-launch You can write like it : while read -p "Press ENTER" ; do python ; done


    -2
    while read ; do python <script> ; done
    Zulu · 2012-02-23 22:29:09 2
  • No command substitution but subshell redirection


    10
    read day month year < <(date +'%d %m %y')
    frans · 2011-07-30 06:06:29 1
  • This version uses read instead of eval.


    52
    read day month year <<< $(date +'%d %m %y')
    putnamhill · 2011-07-29 15:05:19 4
  • You can ask repeatedly for a non-blank password using this function: function read_password() { while [ ! -n "$USER_PASSWORD" ]; do read -s -p"Password: " USER_PASSWORD if [ ! -n "$USER_PASSWORD" ]; then echo "ERROR: You must specify a valid password, please try again" fi echo done } Also you can set a time out (in seconds) to write the password read -t 10 -s -p"Password: " USER_PASSWORD_VARIABLE if [ ! $? -eq 0 ]; then echo "Time out!" fi


    14
    read -s -p"Password: " USER_PASSWORD_VARIABLE; echo
    h3nr1x · 2011-07-20 20:22:42 0
  • Recursively find php files and replace tab characters with spaces. Options: "\*.php" -- replace this with the files you wish to find "expand" -- replace tabs with spaces (use "unexpand" to replace spaces with tabs) "-t4" -- tabs represent 4 spaces Note: The IFS="" in the middle is to prevent 'read' from eating leading/trailing whitespace in filenames.


    -4
    find . -type f -name \*.php | while IFS="" read i; do expand -t4 "$i" > "$i-"; mv "$i-" "$i"; done
    flatcap · 2011-04-08 12:53:14 4
  • Take a folder full of files and split it into smaller folders containing a maximum number of files. In this case, 100 files per directory. find creates the list of files xargs breaks up the list into groups of 100 for each group, create a directory and copy in the files Note: This command won't work if there is whitespace in the filenames (but then again, neither do the alternative commands :-)


    -1
    files -type f | xargs -n100 | while read l; do mkdir $((++f)); cp $l $f; done
    flatcap · 2011-02-15 23:15:16 1
  • Change your drive letter as you wish. Using pv command for speed detect.First of all you must install pv command for usage. http://www.bayner.com/ kerim@bayner.com Show Sample Output


    -1
    cat /dev/sda | pv -r > /dev/null
    kerim · 2011-01-23 22:58:56 2

  • 10
    read -a ARR <<<'world domination now!'; echo ${ARR[2]};
    unefunge · 2010-12-03 16:27:03 2
  • Like 7171, but fixed typo, uses fewer variables, and even more cryptic! Show Sample Output


    4
    read -a A<<<".*.**..*....*** 8 9 5 10 6 0 2 11 7 4";for C in `date +"%H%M"|fold -w1`;do echo "${A:${A[C+1]}:4}";done
    __ · 2010-12-02 22:04:49 1
  • cryptic version Show Sample Output


    2
    read -a A <<<"8 9 5 10 6 0 3 11 7 4";B='.*.**..*....***';for C in $(date +"%H%M"|fold -w1);do echo "${B:${A[C]}:4}";done
    unefunge · 2010-11-26 11:29:23 2
  • This version works across on all POSIX compliant shell variants.


    3
    Confirm() { echo -n "$1 [y/n]? " ; read reply; case $reply in Y*|y*) true ;; *) false ;; esac }
    eikenberry · 2010-11-22 16:54:16 0
  • Returns true if user presses the key. Use it like Confirm "Continue" && do action


    12
    Confirm() { read -sn 1 -p "$1 [Y/N]? "; [[ $REPLY = [Yy] ]]; }
    frans · 2010-11-22 11:01:14 4
  • While going through the source code for the well known ps command, I read about some interesting things.. Namely, that there are a bunch of different fields that ps can try and enumerate for you. These are fields I was not able to find in the man pages, documentation, only in the source. Here is a longer function that goes through each of the formats recognized by the ps on your machine, executes it, and then prompts you whether you would like to add it or not. Adding it simply adds it to an array that is then printed when you ctrl-c or at the end of the function run. This lets you save your favorite ones and then see the command to put in your .bash_profile like mine at : http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Note that I had to do the exec method below in order to pause with read. t () { local r l a P f=/tmp/ps c='command ps wwo pid:6,user:8,vsize:8,comm:20' IFS=' '; trap 'exec 66 exec 66 $f && command ps L | tr -s ' ' >&$f; while read -u66 l >&/dev/null; do a=${l/% */}; $c,$a k -${a//%/} -A; yn "Add $a" && P[$SECONDS]=$a; done } Show Sample Output


    2
    for p in `ps L|cut -d' ' -f1`;do echo -e "`tput clear;read -p$p -n1 p`";ps wwo pid:6,user:8,comm:10,$p kpid -A;done
    AskApache · 2010-10-12 06:42:10 1
  • This shows every bit of information that stat can get for any file, dir, fifo, etc. It's great because it also shows the format and explains it for each format option. If you just want stat help, create this handy alias 'stath' to display all format options with explanations. alias stath="stat --h|sed '/Th/,/NO/!d;/%/!d'" To display on 2 lines: ( F=/etc/screenrc N=c IFS=$'\n'; for L in $(sed 's/%Z./%Z\n/'<<<`stat --h|sed -n '/^ *%/s/^ *%\(.\).*$/\1:%\1/p'`); do G=$(echo "stat -$N '$L' \"$F\""); eval $G; N=fc;done; ) For a similarly powerful stat-like function optimized for pretty output (and can sort by any field), check out the "lll" function http://www.commandlinefu.com/commands/view/5815/advanced-ls-output-using-find-for-formattedsortable-file-stat-info From my .bash_profile -> http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Show Sample Output


    3
    statt(){ C=c;stat --h|sed '/Th/,/NO/!d;/%/!d'|while read l;do p=${l/% */};[ $p == %Z ]&&C=fc&&echo ^FS:^;echo "`stat -$C $p \"$1\"` ^$p^${l#%* }";done|column -ts^; }
    AskApache · 2010-06-11 23:31:03 0
  • This provides a way to sort output based on the length of the line, so that shorter lines appear before longer lines. It's an addon to the sort that I've wanted for years, sometimes it's very useful. Taken from my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Show Sample Output


    2
    sortwc () { local L;while read -r L;do builtin printf "${#L}@%s\n" "$L";done|sort -n|sed -u 's/^[^@]*@//'; }
    AskApache · 2010-05-20 20:13:52 1
  • If you have used bash for any scripting, you've used the date command alot. It's perfect for using as a way to create filename's dynamically within aliases,functions, and commands like below.. This is actually an update to my first alias, since a few commenters (below) had good observations on what was wrong with my first command. # creating a date-based ssh-key for askapache.github.com ssh-keygen -f ~/.ssh/`date +git-$USER@$HOSTNAME-%m-%d-%g` -C 'webmaster@askapache.com' # /home/gpl/.ssh/git-gplnet@askapache.github.com-04-22-10 # create a tar+gzip backup of the current directory tar -czf $(date +$HOME/.backups/%m-%d-%g-%R-`sed -u 's/\//#/g' <<< $PWD`.tgz) . # tar -czf /home/gpl/.backups/04-22-10-01:13-#home#gpl#.rr#src.tgz . I personally find myself having to reference date --help quite a bit as a result. So this nice alias saves me a lot of time. This is one bdash mofo. Works in sh and bash (posix), but will likely need to be changed for other shells due to the parameter substitution going on.. Just extend the sed command, I prefer sed to pretty much everything anyways.. but it's always preferable to put in the extra effort to go for as much builtin use as you can. Otherwise it's not a top one-liner, it's a lazyboy recliner. Here's the old version: alias dateh='date --help|sed "/^ *%%/,/^ *%Z/!d;s/ \+/ /g"|while read l;do date "+ %${l/% */}_${l/% */}_${l#* }";done|column -s_ -t' This trick from my [ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html bash_profile ] Show Sample Output


    21
    alias dateh='date --help|sed -n "/^ *%%/,/^ *%Z/p"|while read l;do F=${l/% */}; date +%$F:"|'"'"'${F//%n/ }'"'"'|${l#* }";done|sed "s/\ *|\ */|/g" |column -s "|" -t'
    AskApache · 2010-04-21 01:22:18 5
  • SH

    cat mod_log_config.c | shmore or shmore < mod_log_config.c Most pagers like less, more, most, and others require additional processes to be loaded, additional cpu time used, and if that wasn't bad enough, most of them modify the output in ways that can be undesirable. What I wanted was a "more" pager that was basically the same as running: cat file Without modifying the output and without additional processes being created, cpu used, etc. Normally if you want to scroll the output of cat file without modifying the output I would have to scroll back my terminal or screen buffer because less modifies the output. After looking over many examples ranging from builtin cat functions created for csh, zsh, ksh, sh, and bash from the 80's, 90s, and more recent examples shipped with bash 4, and after much trial and error, I finally came up with something that satisifed my objective. It automatically adjusts to the size of your terminal window by using the LINES variable (or 80 lines if that is empty) so This is a great function that will work as long as your shell works, so it will work just find if you are booted in single user mode and your /usr/bin directory is missing (where less and other pagers can be). Using builtins like this is fantastic and is comparable to how busybox works, as long as your shell works this will work. One caveat/note: I always have access to a color terminal, and I always setup both the termcap and the terminfo packages for color terminals (and/or ncurses and slang), so for that reason I stuck the tput setab 4; tput setaf 7 command at the beginning of the function, so it only runs 1 time, and that causes the -- SHMore -- prompt to have a blue background and bright white text. This is one of hundreds of functions I have in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html">.bash_profile at http://www.askapache.com/">AskApache.com, but actually won't be included till the next update. If you can improve this in any way at all please let me know, I would be very grateful! ( Like one thing I want is to be able to continue to the next screen by pressing any key instead of now having to press enter to continue) Show Sample Output


    6
    shmore(){ local l L M="`echo;tput setab 4&&tput setaf 7` --- SHMore --- `tput sgr0`";L=2;while read l;do echo "${l}";((L++));[[ "$L" == "${LINES:-80}" ]]&&{ L=2;read -p"$M" -u1;echo;};done;}
    AskApache · 2010-04-21 00:40:37 1
  • hold period (or whatever character) and hit enter after a second. You need to make the next line of periods the same length as the previous line... score starts at 0 and increase each time length of line is same.


    1
    while $8;do read n;[ $n = "$l" ]&&c=$(($c+1))||c=0;echo $c;l=$n;done
    florian · 2010-03-31 00:41:08 0
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