Regular Expressions
| . | match any character |
| ^ | match the beginning of the line |
| $ | match the end of the line |
| [abc] | match a character from list |
| [^abc] | match a charater not in list |
| * | match zero or more of preceding pattern |
| {n,m} | match from n to m of preceding pattern |
| \(...\) | save matched characters |
cut
| -c | cut characters |
| -f | cut fields |
| -d | delimiter (used with -f) |
paste
| -d | delimeter |
sed
| s | substitute |
| -n | no print |
| p | print lines |
| d | delete lines |
tr
| -s | squeeze (remove duplicate delimiters) |
| -d | delete characters |
grep
| -i | case insensitive. Match both upper and lower case letters. |
| -v | print lines that don't match |
| -l | list file names |
| -n | show line numbers |
sort
| -u | no dups |
| -r | reverse order |
| -o | write to file |
| -n | sort numerically |
| +1 | skip field 1 |
| -t | delimeter |
uniq
| -d | show only duplicate lines |
| -c | show count of each line |