Commands by brettalton (5)

  • Convert PNG to GIF

    (relies on 'imagemagick') Convert all .png files to .gif. This can also go the other way if you reverse the file extensions in the command, e.g.: for file in *.gif; do convert "$file" "$(basename $file .gif).png"; done If the file is named 'example1.png' it will be named 'example1.gif' when it is complete.


    4
    for file in *.png; do convert "$file" "$(basename $file .png).gif"; done
    brettalton · 2009-02-15 23:39:08 5
  • Convert PDF to JPG

    (relies on 'imagemagick') This command will convert all .pdf files in a directory into a 800px (wide or height, whichever is smaller) image (with the aspect ratio kept) .jpg. If the file is named 'example1.pdf' it will be named 'example1.jpg' when it is complete. This is a VERY worthwhile command! People pay hundreds of dollars for this in the Windows world. My .jpg files average between 150kB to 300kB, but your's may differ. Show Sample Output


    30
    for file in `ls *.pdf`; do convert -verbose -colorspace RGB -resize 800 -interlace none -density 300 -quality 80 $file `echo $file | sed 's/\.pdf$/\.jpg/'`; done
    brettalton · 2009-02-15 23:27:43 4
  • Extract .daa files with PowerISO

    .daa is a non-standard disk image format that can not be read by any other program. This is how you can extract the files though. PowerISO binary for Linux: http://www.poweriso.com/poweriso-1.3.tar.gz "This is a free utility for linux which can extract, list, and convert image files (including ISO, BIN, DAA, and other formats). Type " poweriso -? " for detailed usage information. File Size: 278KB"


    -2
    ./poweriso extract $USER/file.daa / -od $USER/file_extracted
    brettalton · 2009-02-15 23:19:40 0
  • View your motherboard's ACPI tables (in Debian & Ubuntu)

    In July 2008, there was an uproar over Foxconn motherboards feeding Linux installs incorrect ACPI information (http://ubuntu-virginia.ubuntuforums.org/showthread.php?t=869249). Foxconn has gladly corrected their mistake, but make sure it's not happening on your motherboard! After running the command, just view the 'dsdt.dsl' in any editor you like. Show Sample Output


    -1
    sudo aptitude -y install iasl && sudo cat /sys/firmware/acpi/tables/DSDT > dsdt.dat && iasl -d dsdt.dat
    brettalton · 2009-02-15 23:13:50 0
  • Concatenate (join) video files

    Use mencoder to concatenate (join) multiple video files together. Show Sample Output


    9
    mencoder -forceidx -ovc copy -oac copy -o output.avi video1.avi video2.avi
    brettalton · 2009-02-15 23:05:32 1

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Remove a range of lines from a file

display emerge.log date in a human friendly way
gentoo only or gentoo-like linux distributions.

Copy sparse files
This causes cp to detect and omit large blocks of nulls. Sparse files are useful for implying a lot of disk space without actually having to write it all out. http://en.wikipedia.org/wiki/Sparse_file You can use it in a pipe too: $ dd if=/dev/zero bs=1M count=5 |cp --sparse=always /dev/stdin SPARSE_FILE

Most Commonly Used Grep Options
This is very helpful to place in a shell startup file and will make grep use those options all the time. This example is nice as it won't show those warning messages, skips devices like fifos and pipes, and ignores case by default.

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"

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"

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" }

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

List the most recent dates in reverse-chronological order

Command to logout all the users in one command

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