UNIX and Linix Commands and Utilities

10 UNIX and Linix Commands and Utilities

UNIX and Linux • UNIX • Bell Labs, 1970s • Ken Thompson and Dennis Ritchie • Linux • University of Helsinki • Linus Torvald • Kernel 1.0 released in 1994

Fig. 10.1: UNIX commands are processed by a shell. • Bourne shell • C shell • Bourne Again shell

Fig. 10.2: A UNIX command.

Fig. 10.3: Log on sequence.

Fig. 10.4: Use the passwd utility to change your password.

Fig. 10.5: The date utility.

Fig. 10.6: who displays the names of users currently logged on the system.

Fig. 10.7: UNIX file names. The UNIX file system allows you to save and retrieve files by name.

Fig. 10.7, continued

Fig. 10.8: UNIX uses a hierarchical directory structure.

Directories • Root directory • The system’s lowest level directory • Home directory • The user’s initial directory • Working directory • The user’s current base directory

Fig. 10.9: You must specify a complete pathname to uniquely identify a file.

Fig. 10.10: The pwd (print working directory) command.

Fig. 10.11: The list directory (ls) command.

Fig. 10.12: The files in the referenced directory are listed in alphabetical order.

Fig. 10.13: The ls command.

Fig. 10.14: File type and access permissions.

Fig. 10.15: The make directory (mkdir) utility.

Fig. 10.16: A directory list.

Fig. 10.17: The cd (change directory) command.

Fig. 10.18: The contents of the root directory and of directory users.

Fig. 10.19: The visual editor (vi).

Fig. 10.20: The message displayed by the visual editor after it has created a file.

Fig. 10.21: Use the concatenate (cat) utility to display the contents of one or more files.

Fig. 10.22: Following a catcommand, the contents of all the files are displayed one after another.

Fig. 10.23: The copy (cp) utility.

Fig. 10.24: When a file is copied, its name appears in the new directory.

Fig. 10.25: The same file can be referenced in more than one directory by creating a link.

Wildcard Characters • ? • a single character • * • one or more (usually more) characters

Fig. 10.26: Redirection operators.

Pipes, Filters, and Redirection • Redirection: dynamically changing the default input or output device • Filter: a command that reads the standard input device, filters (or modifies) the data, and writes to the standard output device. • Pipe: An operator that causes one command’s standard output to be used as the standard input to another command.

Fig. 10.27: Redirection.

Fig. 10.28: The sort utility.

Fig. 10.29: With pipes, one utility’s standard output becomes another’s standard input.

Fig. 10.30: A KDE snapshot for a file directory.

Other Useful Commands • lpr contents of file to line printer • vi the visual editor • nroff format text • troff prepare output for phototypesetter • eqn set up equation • tbl format tables • spell spell checker

UNIX and Linix Commands and Utilities

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