Commands by drewk (12)

  • This produces a parseable output of the last day of the month in future or past. Change the '-v-0m' to be a month plus or minus from the current system time. Show Sample Output


    -4
    date -j -v1d -v-0m -v-1d +'%m %d %Y'
    drewk · 2010-03-04 17:47:51 1
  • PDF files are simultaneously wonderful and heinous. They are wonderful in being ubiquitous and mostly being cross platform. They are heinous in being very difficult to work with from the command line, search, grep, use only the text inside the PDF, or use outside of proprietary products. xpdf is a wonderful set of PDF tools. It is on many linux distros and can be installed on OS X. While primarily an open PDF viewer for X, xpdf has the tool "pdftotext" that can extract formated or unformatted text from inside a PDF that has text. This text stream can then be further processed by grep or other tool. The '-' after the file name directs output to stdout rather than to a text file the same name as the PDF. Make sure you use version 3.02 of pdftotext or later; earlier versions clipped lines. The lines extracted from a PDF without the "-layout" option are very long. More paragraphs. Use just to test that a pattern exists in the file. With "-layout" the output resembles the lines, but it is not perfect. xpdf is available open source at http://www.foolabs.com/xpdf/


    27
    pdftotext [file] - | grep 'YourPattern'
    drewk · 2010-02-14 21:42:35 0
  • Bash has a great history system of its commands accessed by the ! built-in history expansion operator (documented elsewhere on this site or on the web). You can combine the ! operator inside the process redirection Very handy. Show Sample Output


    7
    <(!!)
    drewk · 2010-02-06 18:35:10 2
  • The format is JJJJJ YR-MO-DA HH:MM:SS TT L DUT1 msADV UTC(NIST) OTM and is explained more fully here: http://tf.nist.gov/service/acts.htm Show Sample Output


    8
    cat </dev/tcp/time.nist.gov/13
    drewk · 2009-12-03 21:40:14 6

  • -1
    grep -c '^From ' mbox_file
    drewk · 2009-11-07 03:31:05 0
  • Uses curl to download page of membership of US Congress. Use sed to strip HTML then perl to print a line starting with two tabs (a line with a representative) Show Sample Output


    -1
    curl "http://www.house.gov/house/MemberWWW.shtml" 2>/dev/null | sed -e :a -e 's/<[^>]*>//g;/</N;//ba' | perl -nle 's/^\t\t(.*$)/ $1/ and print;'
    drewk · 2009-09-24 23:37:36 0
  • How often do you make a directory (or series of directories) and then change into it to do whatever? 99% of the time that is what I do. This BASH function 'md' will make the directory path then immediately change to the new directory. By using the 'mkdir -p' switch, the intermediate directories are created as well if they do not exist. Show Sample Output


    32
    md () { mkdir -p "[email protected]" && cd "[email protected]"; }
    drewk · 2009-09-24 16:09:19 5
  • The sort utility is well used, but sometimes you want a little chaos. This will randomize the lines of a text file. BTW, on OS X there is no | sort -R option! There is also no | shuf These are only in the newer GNU core... This is also faster than the alternate of: | awk 'BEGIN { srand() } { print rand() "\t" $0 }' | sort -n | cut -f2- Show Sample Output


    0
    cat ~/SortedFile.txt | perl -wnl -e '@f=<>; END{ foreach $i (reverse 0 .. $#f) { $r=int rand ($i+1); @f[$i, $r][email protected][$r,$i] unless ($i==$r); } chomp @f; foreach $line (@f){ print $line; }}'
    drewk · 2009-09-24 15:42:43 2
  • The backtick operator, in general, will execute the text inside the backticks. On OS X, the pbpaste command will put the contents of the OS X clipboard to STDOUT. So if you put backticks around pbpaste, the text from the OS X clipboard is executed. If you add the pipeline | pbcopy, the output from executing the command on the clipboard is placed back on the clipboard. Note: make sure the clipboard is text only. Show Sample Output


    7
    `pbpaste` | pbcopy
    drewk · 2009-09-21 23:10:11 3
  • This pipeline will find, sort and display all files based on mtime. This could be done with find | xargs, but the find | xargs pipeline will not produce correct results if the results of find are greater than xargs command line buffer. If the xargs buffer fills, xargs processes the find results in more than one batch which is not compatible with sorting. Note the "-print0" on find and "-0" switch for perl. This is the equivalent of using xargs. Don't you love perl? Note that this pipeline can be easily modified to any data produced by perl's stat operator. eg, you could sort on size, hard links, creation time, etc. Look at stat and just change the '9' to what you want. Changing the '9' to a '7' for example will sort by file size. A '3' sorts by number of links.... Use head and tail at the end of the pipeline to get oldest files or most recent. Use awk or perl -wnla for further processing. Since there is a tab between the two fields, it is very easy to process. Show Sample Output


    3
    find $HOME -type f -print0 | perl -0 -wn -e '@f=<>; foreach $file (@f){ (@el)=(stat($file)); push @el, $file; push @files,[ @el ];} @o=sort{$a->[9]<=>$b->[9]} @files; for $i (0..$#o){print scalar localtime($o[$i][9]), "\t$o[$i][-1]\n";}'|tail
    drewk · 2009-09-21 22:11:16 5
  • This finds all the PowerPC apps recognized by OS X. A better version is: system_profiler SPApplicationsDataType 2> /dev/null | perl - wnl -e '$i=$j=$k=$p=0; @al=; [email protected]; while($j s[$i].=$al[$j]; $i++ if ($al[$j]) =~ /^\s\s\s\s\S.*:$/; $j++} while($k apps[$k++]; if (/Kind: PowerPC/s) {print; $p++;}} print "$i applications, $p P owerPC applications\n\n"' but that is more than 255 characters...


    0
    system_profiler SPApplicationsDataType | perl -nl -e '@al=<>; [email protected]; while($j<$c){ $apps[$i].=$al[$j]; $i++ if ($al[$j] ) =~ /^\s\s\s\s\S.*:$/; $j++} while($k<$i){ $_=$apps[$k++]; if (/Kind: PowerPC/s) {print;}}'
    drewk · 2009-09-06 20:56:48 0
  • diff is designed to compare two files. You can also compare directories. In this form, bash uses 'process substitution' in place of a file as an input to diff. Each input to diff can be filtered as you choose. I use find and egrep to select the files to compare.


    3
    diff <(cd /path-1; find . -type f -print | egrep -i '\.m4a$|\.mp3$') <(cd /path-2; find . f -print | egrep -i '\.m4a$|\.mp3$')
    drewk · 2009-08-17 00:49:31 1

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shell bash iterate number range with for loop

Make a thumbnail image of first page of a PDF.
convert is included in ImageMagick. Don't forget the [X] (where X is the page number). [0] is the first page of the PDF.

Edit the last or previous command line in an editor then execute
If you would like to edit a previous command, which might be long and complicated, you can use the fc (I think it stands for fix command). Invoke fc alone will edit the last command using the default editor (specified by $FCEDIT, $EDITOR, or emacs, in that order). After you make the changes in the editor, save and exit to execute that command. The fc command is more flexible than what I have described. Please 'man bash' for more information.

exclude a column with cut
Show all columns except 5th. This might help you save some typing if you are trying to exclude some columns from the output.

List hostnames of all IPs

Open a file with specified application.
This command require mac os x.

Save your open windows to a file so they can be opened after you restart
This will save your open windows to a file (~/.windows). To start those applications: $ cat ~/.windows | while read line; do $line &; done Should work on any EWMH/NetWM compatible X Window Manager. If you use DWM or another Window Manager not using EWMH or NetWM try this: $ xwininfo -root -children | grep '^ ' | grep -v children | grep -v '' | sed -n 's/^ *\(0x[0-9a-f]*\) .*/\1/p' | uniq | while read line; do xprop -id $line _NET_WM_PID | sed -n 's/.* = \([0-9]*\)$/\1/p'; done | uniq -u | grep -v '^$' | while read line; do ps -o cmd= $line; done > ~/.windows

Find files that have been modified on your system in the past 60 minutes
Useful mainly for debugging or troubleshooting an application or system, such as X11, Apache, Bind, DHCP and others. Another useful switch that can be combined with -mmin, -mtime and so forth is -daystart. For example, to find files that were modified in the /etc directory only yesterday: $ sudo find /etc -daystart -mtime 1 -type f

get delicious bookmarks on your shell (text version :-))
a variation of avi4now's command - thanks by the way!

Rip DVD to YouTube ready MPEG-4 AVI file using mencoder
Rip DVD to YouTube ready AVI file, using MPEG-4 video codec and MP3 audio codec. Resizes to 320x240 and deinterlaces as needed.


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