Useful programs
From Linux 101, The beginner's guide to all things Linux.
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[edit] Small programs
The most commonly used programs.
TODO: Sort by section, wikify to articles.
cat less grep find echo man ls head tail chmod,chgrp,chown cp mv dmesg kill mkdir tar rm lsmod modprobe mount umount df ln
[edit] Cron
Cron is a system scheduling tool. It can be used to schedule recurrent tasks like for example making backups every sunday at midnight.
[edit] At
at is used to schedule a single task. If you want a task to be run at certain times indefinitely, you should use cron.
To schedule a task, execute:
-
at <time>
To schedule a command at 7:00 PM, use:
-
at 7:00 pm
Then type the commands you want to be executed and exit with CTRL-D (meaning EOF, or end of file). You can also pass the file to execute using the -f option.
To list the current scheduled jobs:
-
atq
To remove a job:
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atrm <job #>
You can also do some things like specify executing the command a number of minutes, hours, days, or weeks by doing something like:
-
at now + 3 hours
Further examples are given in man at.
[edit] Sed
Sed (which stands for Stream EDitor) is a simple but powerful computer program used to apply various pre-specified textual transformations to a sequential stream of text data.
[edit] Awk
Awk is a general purpose computer language that is designed for processing text based data, either in files or data streams. The name AWK is derived from the surnames of its authors -- Alfred V. Aho, Peter J. Weinberger, and Brian W. Kernighan.
