Commands tagged ps1 (7)

  • Alias HEAD for automatic smart output

    Run the alias command, then issue ps aux | head and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand. ${LINES:-`tput lines 2>/dev/null||echo -n 12`} Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the deafault of 12 (-2 = 10). The default for HEAD is to output the first 10 lines, this alias changes the default to output the first x lines instead, where x is the number of lines currently displayed on your terminal - 2. The -2 is there so that the top line displayed is the command you ran that used HEAD, ie the prompt. Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( https://www.askapache.com/linux/bash-power-prompt/ ) 275MB/748MB [7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~ In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device. Show Sample Output


    27
    alias head='head -n $((${LINES:-`tput lines 2>/dev/null||echo -n 12`} - 2))'
    AskApache · 2010-04-08 22:37:06 14
  • hanukkah colored bash prompt

    blue and yellow colored bash prompt for a Hanukkah celebration on your box


    3
    export PS1="\e[0;34m[\u\e[0;34m@\h[\e[0;33m\w\e[0m\e[0m\e[0;34m]#\e[0m "
    decept · 2009-12-13 18:35:06 8
  • Command to Show a List of Special Characters for bash prompt (PS1)

    I use this command (PS1) to show a list bash prompt's special characters. I tested it against A flavor of Red Hat Linux and Mac OS X Show Sample Output


    3
    alias PS1="man bash | sed -n '/ASCII bell/,/end a sequence/p'"
    haivu · 2010-01-15 23:39:28 3
  • Colour part of your prompt red to indicate an error

    If the return code from the last command was greater than zero, colour part of your prompt red. The commands give a prompt like this: [user current_directory]$ After an error, the "[user" part is automatically coloured red. Tested using bash on xterm and terminal. Place in your .bashrc or .bash_profile.


    3
    export PROMPT_COMMAND='if (($? > 0)); then echo -ne "\033[1;31m"; fi'; export PS1='[\[\]\u\[\033[0m\] \[\033[1;34m\]\w\[\033[0m\]]\$ '
    quintic · 2010-08-25 21:19:30 3
  • Add the time to BASH prompt

    Adds the time in 12hr AM/PM format to the beginning of a prompt. Change \@ to \t for 24-hour time or \T for 12hr without AM/PM. To keep the time the next time you open a terminal, edit ~/.bashrc and stick the command at the bottom. Show Sample Output


    1
    export PS1="(\@) $PS1"
    cmdq · 2010-11-22 04:50:21 5
  • Cool PS1 with host, time, path and user. With color!

    A simple PS1, ready to be used. Just paste in your ~/.bashrc Show Sample Output


    0
    export PS1="[\[\e[1;32m\]\u\[\e[m\]\[\e[1;31m\]@\[\e[m\]\[\e[3;35m\]\H\[\e[m\] \[\e[1;30m\]| \[\e[m\]\[\e[1;34m\]\w\[\e[m\] \[\e[1;29m\]\t\[\e[m\]]\[\e[1;33m\]$\[\e[m\]"
    thelaser · 2017-03-24 14:21:20 15
  • Colour part of your prompt red to indicate an error


    -2
    export PS1='[\[\e[36;1m\]\u@\[\e[32;1m\]\h \[\e[31;1m\]\w]# \[\e[0m\]'
    bakhru · 2011-04-16 00:58:51 5

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Create the directoty recursively

STAT Function showing ALL info, stat options, and descriptions
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/'

doing some floating point math

ROT13 whole file in vim.
gg puts the cursor at the begin g? ROT13 until the next mov G the EOF

list file descriptors opened by a process
Useful for examining hostile processes (backdoors,proxies)

Group OR'd commands where you expect only one to work
Something to stuff in an alias when you are working in multiple environments. The double-pipe OR will fall through until one of the commands succeeds, and the rest won't be executed. Any STDERR will fall out, but the STDOUT from the correct command will bubble out of the parenthesis to the less command, or some other command you specify.

Show a curses based menu selector
Not so much handy by itself, but very nice in shell scripts. This makes you a handy ncurses based checklist. Much like terminal installers, just use the arrow keys and hit 'Space' to adjust the selections. Returns all selected tags as strings, with no newline at the end. So, your output will be something like: "one" "two" "three" "four" "etc" For those who prefer bash expansion over gratuitious typing: $ whiptail --checklist "Simple checkbox menu" 12 35 3 $(echo {one,two,three,four}" '' 0"} ) Things to note: The height must includes the outer border and padding: add 7 to however many items you want to show up at the same time. If the status is 1, it will be selected by default. anything else, will be deselected.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Find non-ASCII and UTF-8 files in the current directory

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