Commands by brettalton (5)

  • (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.

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

    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
  • .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: "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"

    ./poweriso extract $USER/file.daa / -od $USER/file_extracted
    brettalton · 2009-02-15 23:19:40 0
  • In July 2008, there was an uproar over Foxconn motherboards feeding Linux installs incorrect ACPI information ( 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

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

    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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Quickly get summary of sizes for files and folders
Use this as a quick and simple alternative to the slightly verbose "du -s --max-depth=1"

Transforms a file to all uppercase.
Transforms a file to all uppercase.

rgrep: recursive grep without .svn
Only excludes .svn from filenames.

Stream YouTube URL directly to mplayer.
Streams youtube video with v=ID directly into the mplayer. If exists, it uses the HD-quality stream. If you don't want to watch it in HD-quality, you can use the shorter form: $ID=52DnUo6wJto; mplayer -fs $(echo "$ID$(wget -qO - ''$ID | perl -ne 'print $1."&asv=" if /^.*(&t=.*?)&.*$/')")

Block an IP address from connecting to a server
This appends (-A) a new rule to the INPUT chain, which specifies to drop all packets from a source (-s) IP address.

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Get full from half remembered commands
Show all commands having the part known by you. Eg: $apropos pdf | less

Grep syslog today last hour
Uses date to grep de logfile for today and uses it to get the last hour logs. Can be used to get last minute logs or today's logs.

tcpdump sniff pop3,imap,smtp and http

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