Appendix B. Special Shell Characters and Variables
Mac OS X offers several different shells you can use to enter commands and run scripts. Chapter 2 helps you become comfortable working in the shell. This appendix provides a reference of the numerous characters and variables that have special meaning to particular shells (such as the bash shell) or are available on most shells. Many of those elements are referenced in Table B-1 (Special Shell Characters) and Table B-2 (Shell Environment Variables).
Using Special Shell Characters
You can use special characters from the shell to match multiple files, save some keystrokes, or perform special operations. Table B-1 shows some shell special characters that you may find useful.
Table B.1. Special Shell Characters
Character | Description |
|---|---|
| Match any string of characters. |
| Match any one character. |
| Match any character enclosed in the braces. |
| Remove special meaning of characters between quotes. Variables are not expanded. |
| Same as simple quotes except for the escape characters ( |
| Escape character to remove the special meaning of the character that follows. |
| Refers to the |
| Value of the shell variable PWD or the working directory ( |
| Refers to the previous working directory ( |
| Refers to the current working directory. |
| Refers to the directory above the current directory. Can be used repeatedly ... |
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