Commands tagged Shell programming (6)

  • Working random fact generator

    Though without infinite time and knowledge of how the site will be designed in the future this may stop working, it still will serve as a simple straight forward starting point. This uses the observation that the only item marked as strong on the page is the single logical line that includes the italicized fact. If future revisions of the page show failure, or intermittent failure, one may simply alter the above to read. wget randomfunfacts.com -O - 2>/dev/null | tee lastfact | grep \<strong\> | sed "s;^.*<i>\(.*\)</i>.*$;\1;" The file lastfact, can then be examined whenever the command fails.


    13
    wget randomfunfacts.com -O - 2>/dev/null | grep \<strong\> | sed "s;^.*<i>\(.*\)</i>.*$;\1;"
    tali713 · 2010-03-30 23:49:30 1
  • Simple XML tag extract with sed

    Limited, but useful construct to extract text embedded in XML tags. This will only work if bar is all on one line. If nobody posts an alternative for the multiline sed version, I'll figure it out later...


    4
    sed -n 's/.*<foo>\([^<]*\)<\/foo>.*/\1/p'
    recursiverse · 2009-07-23 07:59:30 0
  • Alias to edit and source your .bashrc file

    Place the line above in your ~/.bahsrc file. Now every time you issue the 'vb' command, you invoke the vim editor to edit it, then source it so the changes take effect immediately. Notes: * This mechanism is not working well if your .bashrc contains commands that should not be sourced more than once. * This trick also work for your csh or tclsh users: place the following line in your ~/.cshrc file: alias vc 'vim ~/.cshrc; source ~/.cshrc Thank you adzap for pointing out the missing quote


    2
    alias vb='vim ~/.bashrc; source ~/.bashrc'
    haivu · 2009-03-02 21:01:49 4
  • Working random fact generator

    extension to tali713's random fact generator. It takes the output & sends it to notify-osd. Display time is proportional to the lengh of the fact.


    2
    wget randomfunfacts.com -O - 2>/dev/null | grep \<strong\> | sed "s;^.*<i>\(.*\)</i>.*$;\1;" | while read FUNFACT; do notify-send -t $((1000+300*`echo -n $FUNFACT | wc -w`)) -i gtk-dialog-info "RandomFunFact" "$FUNFACT"; done
    mtron · 2010-04-02 09:43:32 1
  • Display all shell functions set in the current shell environment

    Uses the shell builtin `declare` with the '-f' flag to output only functions to grep out only the function names. You can use it as an alias or function like so: alias shfunctions="builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'" shfunctions () { builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'; } Show Sample Output


    2
    builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'
    sciro · 2018-07-23 05:24:04 0
  • Working random fact generator

    This is a working version, though probably clumsy, of the script submitted by felix001. This works on ubuntu and CygWin. This would be great as a bash function, defined in .bashrc. Additionally it would work as a script put in the path. Show Sample Output


    0
    lynx -dump randomfunfacts.com | grep -A 3 U | sed 1D
    xizdaqrian · 2009-05-05 07:52:10 8

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Easily scp a file back to the host you're connecting from
Place in .bashrc and invoke like this: "mecp /path/to/file", and it will copy the specified file(s) back to the desktop of the host you're ssh'ing in from. To easily upload a file from the host you're ssh'ing in from use this: ucp (){ scp ${SSH_CLIENT%% *}:Desktop/upload/* .; }

create an emergency swapfile when the existing swap space is getting tight
Create a temporary file that acts as swap space. In this example it's a 1GB file at the root of the file system. This additional capacity is added to the existing swap space.

cut audio file

Write on the console without being registered
just use a space to prevent commands from being recorded in bash's history on most systems

Use result of the last command
\$ which python /usr/bin/python \$ ll `!!` lrwxrwxrwx 1 root root 9 2010-11-08 22:01 /usr/bin/python -> python2.6

umount --rbind mount with submounts
Original: https://bugzilla.redhat.com/show_bug.cgi?id=194342

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"

Virtual Console lock program
vlock command locks the current console by default. Also you can lock all the consoles on the server by using -a parameter. For details, pl man vlock. ps: Generally speaking , system will not install vlock programme . So you should use ' $ sudo apt-get install vlock ' to install vlock .

Search for an active process without catching the search-process
This does the same thing as many of the 'grep' based alternatives but allows a more finite control over the output. For example if you only wanted the process ID you could change the command: $ ps -ef | awk '/mingetty/ && !/awk/ {print $2}' If you wanted to kill the returned PID's: $ ps -ef | awk '/mingetty/ && !/awk/ {print $2}' | xargs -i kill {}

search string in _all_ revisions

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