Commands by thoughtcriminal (1)

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archlinux:Delete packages from pacman cache that are older than 7 days
Sometimes my /var/cache/pacman/pkg directory gets quite big in size. If that happens I run this command to remove old package files. Packages that we're upgraded in last N days are kept in case you are forced to downgrade a specific package. The command is obviously Arch Linux related.

Rename files in batch

Read null character seperated fields from a file
Handle any bad named file which contains ",',\n,\b,\t,` etc Store the file name as null character separated list $find . -print0 >name.lst and retrieve it using $read -r -d "" Eg: $find . -print0 >name.lst; $cat name.lst| while IFS="" read -r -d "" file; $do $ls -l "$file"; $done

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" }

Get the size of all the directories in current directory (Sorted Human Readable)
as per eightmillion's comment. Simply economical :)

invoke MATLAB functions from command line
`-r script.m` also possible

In place line numbering
Add permanent line numbers to a file without creating a temp file. The rm command deletes file10 while the nl command works on the open file descriptor of file10 which it outputs into a new file again named file10. The new file10 will now be numbered in the same directory with the same file name and content as before, but it will in fact be a new file, using (ls -i) to show its inode number will prove this.

See system users

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" }

Make vim open in tabs by default (save to .profile)
I always add this to my .profile rc so I can do things like: "vim *.c" and the files are opened in tabs.

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