| Symbol/Command | Meaning/Action |
|---|
| > | Redirect output. |
| >> | Append to file. |
| < | Redirect input. |
| << | “Here” document (redirect input). |
| | | Pipe output. |
| |& | Start a coprocess. Korn shell only. |
| & | Run process in background. |
| ; | Separate commands on same line. |
| * | Match any character(s) in filename. |
| ? | Match single character in filename. |
| [ ] | Match any characters enclosed. |
| ( ) | Execute in subshell. |
| ‘ ‘ | Substitute output of enclosed command. |
| " " | Partial quote (allows variable and command expansion). |
| ' ' | Full quote (no expansion). |
| \ | Quote following character. |
| $var | Use value for variable. |
| $$ | Process ID. |
| $0 | Command name. |
| $n | nth argument (0  n 9). |
| $* | All arguments as simple words. |
| # | Begin comment. |
| bg | Background execution. |
| break | Break from loop statements. |
| cd | Change directory. |
| continue | Resume a program loop. |
| echo | Display output. |
| eval | Evaluate arguments. |
| exec | Execute a new shell. |
| fg | Foreground execution. |
| jobs | Show active jobs. |
| kill | Terminate running jobs. |
| shift | Shift positional parameters. |
| stop | Suspend a background job. |
| suspend | Suspend a foreground job (such as a shell created by su). |
| time | Time a command. |
| umask | Set default file permissions for new files. |
| unset | Erase variable or function definitions. |
| wait | Wait for a background job to finish. |
