Commands tagged environment (13)

  • Print environment (system) information using Perl.


    3
    perl -e 'print map { $_ .= "$ENV{$_}\n" } (keys %ENV)'
    MarxBro · 2012-10-13 23:38:28 7
  • This uses some tricks I found while reading the bash man page to enumerate and display all the current environment variables, including those not listed by the 'env' command which according to the bash docs are more for internal use by BASH. The main trick is the way bash will list all environment variable names when performing expansion on ${!A*}. Then the eval builtin makes it work in a loop. I created a function for this and use it instead of env. (by aliasing env). This is the function that given any parameters lists the variables that start with it. So 'aae B' would list all env variables starting wit B. And 'aae {A..Z} {a..z}' would list all variables starting with any letter of the alphabet. And 'aae TERM' would list all variables starting with TERM. aae(){ local __a __i __z;for __a in "$@";do __z=\${!${__a}*};for __i in `eval echo "${__z}"`;do echo -e "$__i: ${!__i}";done;done; } And my printenv replacement is: alias env='aae {A..Z} {a..z} "_"|sort|cat -v 2>&1 | sed "s/\\^\\[/\\\\033/g"' From: http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Show Sample Output


    2
    for _a in {A..Z} {a..z};do _z=\${!${_a}*};for _i in `eval echo "${_z}"`;do echo -e "$_i: ${!_i}";done;done|cat -Tsv
    AskApache · 2010-10-27 07:16:54 6
  • Grabs the cmdline used to execute the process, and the environment that the process is being run under. This is much different than the 'env' command, which only lists the environment for the shell. This is very useful (to me at least) to debug various processes on my server. For example, this lets me see the environment that my apache, mysqld, bind, and other server processes have. Here's a function I use: aa_ps_all () { ( cd /proc && command ps -A -opid= | xargs -I'{}' sh -c 'test $PPID -ne {}&&test -r {}/cmdline&&echo -e "\n[{}]"&&tr -s "\000" " "<{}/cmdline&&echo&&tr -s "\000\033" "\nE"<{}/environ|sort&&cat {}/limits' ); } From my .bash_profile at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Show Sample Output


    1
    cd /proc&&ps a -opid=|xargs -I+ sh -c '[[ $PPID -ne + ]]&&echo -e "\n[+]"&&tr -s "\000" " "<+/cmdline&&echo&&tr -s "\000\033" "\nE"<+/environ|sort'
    AskApache · 2010-10-22 02:34:33 15
  • Same as previous but compatible with BSD/IPSO


    1
    ps ewwo command PID | tr ' ' '\n' | grep \=
    egreSS · 2011-09-15 12:07:46 4
  • Normally the bash builtin command 'set' displays all vars and functions. This just shows the vars. Useful if you want to see different output then env or declare or export. Alias 'sete' shows sets variables alias sete='set|sed -n "/^`declare -F|sed -n "s/^declare -f \(.*\)/\1 ()/p;q"`/q;p"' Alias setf shows the functions. alias setf='set|sed -n "/^`declare -F|sed -n "s/^declare -f \(.*\)/\1 ()/p;q"`/,\$p"' Also see: http://www.commandlinefu.com/commands/view/6899/print-all-environment-variables-including-hidden-ones At the very least, some cool sed commands! From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Show Sample Output


    0
    alias sete='set|sed -n "/^`declare -F|sed -n "s/^declare -f \(.*\)/\1 ()/p;q"`/q;p"'
    AskApache · 2010-11-17 23:58:01 11
  • Python virtual environment creation.


    0
    $sudo aptitude install python-virtualenv; virtualenv --no-site-packages jpaenv; source jpaenv/bin/activate
    moulip · 2011-04-21 08:28:18 4
  • This exports all lines of input file as environment variables, assuming each line is like these: OH=YEAH FU=UUUU


    0
    while read line; do export $line; done < <(cat input)
    dario · 2013-03-15 08:14:04 11
  • Sometimes there are just no variables such as $DESKTOP_SESSION, $GDMSESSION, or $WINDOWMANAGER. Show Sample Output


    0
    ls -l /usr/share/xsessions/
    puresky · 2014-01-17 05:09:18 8
  • Normally executing 'set' returns a vast amount of information, including the source code of every function and variable within the environment - including those that are part of the shell. By using the -o posix argument, bash runs temporarily in POSIX mode for this command, which simplifies expressions and leaves out the shell's own functions and definitions - leaving a much smaller, more useful list. Show Sample Output


    0
    alias allvars=' ( set -o posix; set ) | less'
    incidentnormal · 2016-03-04 14:04:45 14

  • 0
    eval "unset $(printenv | grep -ioP '(?:https?|no)_proxy' | tr '\n' ' ')"
    acavagni · 2019-06-28 10:40:41 37
  • This function is used to set environmental variables from a list of alternatives depending on what's installed on the system. It returns the first program found in the list. Example usage: export BROWSER=$(find_alternatives chromium-browser google-chrome opera firefox firefox-bin iceweasel konqueror w3m lynx) . export EDITOR=$(find_alternatives vim nano pico emacs kate) . export PAGER=$(find_alternatives vimpager less most more pg)


    -1
    find_alternatives(){ for i;do which "$i" >/dev/null && { echo "$i"; return 0;};done;return 1;}
    eightmillion · 2011-01-06 19:53:46 4

  • -1
    printenv
    tatwright · 2012-10-14 17:47:18 5

  • -1
    perl -e 'print "$_=$ENV{$_}\n" for keys %ENV'
    sgikas · 2012-11-12 13:14:28 5

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Which processes are listening on a specific port (e.g. port 80)
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Cryptographically secure 32-bit RNG in strict ZSH
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Run a command when a file is changed

Add 10 random unrated songs to xmms2 playlist
If you're like me and want to keep all your music rated, and you use xmms2, you might like this command. I takes 10 random songs from your xmms2 library that don't have any rating, and adds them to your current playlist. You can then rate them in another xmms2 client that supports rating (I like kuechenstation). I'm pretty sure there's a better way to do the grep ... | sed ... part, probably with awk, but I don't know awk, so I'd welcome any suggestions.

Change every instance of OLD to NEW in file FILE
Very quick way to change a word in a file. I use it all the time to change variable names in my PHP scripts (sed -i 's/$oldvar/$newvar/g' index.php)

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Returns logs between HH:M[Mx-My], for example, between 13:40 and 13:45.

pretend to be busy in office to enjoy a cup of coffee
just make some data scrolling off the terminal. wow.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Create a new file

Listen to a song from youtube with youtube-dl and mpv
Explanation Firstly the function checks if user gave it any input, and notifies the user if they failed to do so. If user has inputed a search string, the function will call upon youtube-dl to find url of the audio of the first matching youtube video and play that with mpv. Call function by wrapping search string in quotes: listen-to-yt "sultans of swing" You have to paste the line in your .zshrc and source .zshrc for it to work. Limitations The dependancies are youtube-dl and mpv. this oneliner is stolen from http://www.bashoneliners.com/oneliners/302/


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