| Removable Media |
| How to eject a mounted CDROM? (alternative solution)
| $ eject /mnt/cdrom |
| Printing |
| How to print a text file through a default postscript printer?
| $ a2ps file |
| How to print a file with 2 shrinked pages per sheet?
| $ mpage -2 file |
| 4 shrinked pages per sheet?
| $ mpage file |
| Repetitive Tasks |
| How to remove all symbolic links in a directory? (alternative solution)
| $ for i in *; do [ -L $i ] && rm $i; done |
| How to create 10 empty files (each with a numbered name) in a directory?
| $ for i in $(seq 1 10); do touch $i.txt; done |
| Finder and Executor |
| How to find all *.txt files under directory /tmp?
| $ find /tmp -name '*.txt' |
| How to gnu-zip all *.txt files under home directory (sub-directory excluded)?
| $ find $HOME -name '*.txt' -maxdepth 1 | xargs gzip |
| Perl |
| Simple Calculator
| $ perl -l -e 'print 1024 * 1024' |
| String Replacement for Multiple Files
| $ perl -p -i -e 's/XFree86/x.org/g' file1.txt ... |
| Cron Job Scheduler | (common users need authorization from super-users to use) |
| Edit cron jobs (example)
| $ crontab -e |
| View current cron jobs
| $ crontab -l |