Commands tagged bash (821)

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Revert an SVN file to previous revision
M - current revision, N - older revision

Resize all JPEGs in a directory
This command requires the imagemagick libraries and will resize all files with the .jpg extension to a width of 1024 pixels and will keep the same proportions as the original image.

Delete all local git branches that have been merged
This checks if the branch has been merged with master and then will delete the ones that have been. Keeps your local git repo nice and clean from all the branches.

Line Separator That is Width of Terminal
Creates a line seperator that will be the width of your window.

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.

Poor's man Matrix script
This creates a matrix of letters that run forever until you hit Ctrl-C simulating "The Matrix" effect... just for fun :) You may want to try the -n and -y switch to change the "FX" LOL! e.g.: pwgen -ny 3

Number of CPU's in a system
This appears to do the same. Utility is verified to be present on Ubuntu and OpenSuse out-of-the-box.

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" }

Use /dev/full to test language I/O-failsafety
The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation. In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.

Get a list of IP Addresses that have failed to login via SSH
This command shows a sorted list of the IP addresses from which there have been authentication errors via SSH (possible script kiddies trying to gain access to your server), it eliminates duplicates so it's easier to read, but you can remove the "uniq" command at the end, or even do a "uniq -c" to have a count of how many times each IP address shows in the log (the path to the log may vary from system to system)


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