Commands tagged ksh (12)

  • If you should happen to find yourself needing some binary numbers, this is a quickie way of doing it. If you need more digits, just add more "{0..1}" sequences for each digit you need. You can assign them to an array, too, and access them by their decimal equivalent for a quickie binary to decimal conversion (for larger values it's probably better to use another method). Note: this works in bash, ksh and zsh. For zsh, though, you'll need to issue a setopt KSH_ARRAYS to make the array zero-based. binary=({0..1}{0..1}{0..1}{0..1}) echo ${binary[9]} Show Sample Output


    18
    echo {0..1}{0..1}{0..1}{0..1}
    dennisw · 2009-06-23 17:30:20 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
  • works on all unices. Show Sample Output


    4
    function nowrap { export COLS=`tput cols` ; cut -c-$COLS ; unset COLS ; }
    mobidyc · 2009-09-11 15:07:00 6
  • Convert some decimal numbers to binary numbers. You could also build a general base-converter: function convBase { echo "ibase=$1; obase=$2; $3" | bc; } then you could write function decToBun { convBase 10 2 $1; } Show Sample Output


    4
    function decToBin { echo "ibase=10; obase=2; $1" | bc; }
    woxidu · 2009-11-24 22:57:58 0
  • Specify the size in bytes using the 'c' option for the -size flag. The + sign reads as "bigger than". Then execute du on the list; sort in reverse mode and show the first 10 occurrences. Show Sample Output


    2
    find /myfs -size +209715200c -exec du -m {} \; |sort -nr |head -10
    arlequin · 2011-07-07 21:12:46 0
  • fcd : file change directory A bash function that takes a fully qualified file path and cd's into the directory where it lives. Useful on the commadline when you have a file name in a variable and you'd like to cd to the directory to RCS check it in or look at other files associated with it. Will run on any ksh, bash, likely sh, maybe zsh. Show Sample Output


    1
    function fcd () { [ -f $1 ] && { cd $(dirname $1); } || { cd $1 ; } pwd }
    relay · 2009-09-03 18:58:13 0
  • Creates the .ssh directory on the remote host with proper permissions, if it doesnt exist. Appends your public key to authorized_keys, and verifies it has proper permissions. (if it didnt exist it may have been created with undesireable permissions). *Korn shell syntax, may or may not work with bash


    0
    ssh <user>@<host> 'mkdir -m 700 ~/.ssh; echo ' $(< ~/.ssh/id_rsa.pub) ' >> ~/.ssh/authorized_keys ; chmod 600 ~/.ssh/authorized_keys'
    Halki · 2011-10-03 15:59:43 0
  • Had trouble with the other function, because of missing semicolons. (According to my bash on OS X)


    0
    function cdf () { [ -f $1 ] && { cd $(dirname $1); } || { cd $1 ; }; pwd; };
    Josso · 2012-09-08 10:50:58 1
  • This command is used to verify a sha256sum-formatted file hash list on IBM AIX or any other UNIX-like OS that has openssl but doesn't have sha256sum by default. Steps: 1: Save to the filesystem a script that: A: Receives as arguments the two parts of one line of a sha256sum listing B: Feeds a file into openssl on SHA256 standard input hash calculation mode, and saves the result C: Compares the calculated hash against the one received as argument D: Outputs the result in a sha256sum-like format 2: Make the script runnable 3: Feed the sha256sum listing to xargs, running the aforementioned script and passing 2 arguments at a time Show Sample Output


    0
    echo '#! /usr/bin/ksh\ncat $2 | openssl dgst -sha256 | read hashish; if [[ $hashish = $1 ]]; then echo $2: OK; else echo $2: FAILED; fi;' > shacheck; chmod +x shacheck; cat hashishes.sha256 | xargs -n 2 ./shacheck;
    RAKK · 2013-09-18 21:51:20 2
  • tput rmam will disable line wrapping so that long lines are truncated to width of the terminal ($COLUMNS). tput smam will re-enable wrapping. I've always used tput in bash scripts but I guess it works on the command line too. Doesn't work in all terminals. See http://www.gnu.org/software/termutils/manual/termutils-2.0/html_chapter/tput_1.html


    0
    tput rmam
    kennyld · 2014-02-26 07:06:37 0
  • With this command you can use shell variables inside sed scripts. This is useful if the script MUST remain in an external file, otherwise you can simply use an inline -e argument to sed.


    -1
    expanded_script=$(eval "echo \"$(cat ${sed_script_file})\"") && sed -e "${expanded_script}" your_input_file
    giuseppe_rota · 2009-05-07 14:21:14 0
  • search argument in PATH accept grep expressions without args, list all binaries found in PATH Show Sample Output


    -1
    function sepath { echo $PATH |tr ":" "\n" |sort -u |while read L ; do cd "$L" 2>/dev/null && find . \( ! -name . -prune \) \( -type f -o -type l \) 2>/dev/null |sed "s@^\./@@" |egrep -i "${*}" |sed "s@^@$L/@" ; done ; }
    mobidyc · 2009-09-11 15:03:22 2

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A fun thing to do with ram is actually open it up and take a peek. This command will show you all the string (plain text) values in ram
cat? dd? RTFM

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This could be added to .bashrc. Background: Linux usually saves history only on clean exit of shell. If shell ends unclean, history is lost. Also numerous terminals might confuse their history. With this variable set, history is immedeately written, accessible to all other open shells.


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