Linux in a Nutshell, Fifth Edition

test | 687

Bash and Korn

This is the Title of the Book, eMatter Edition

Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

suspend

suspend [-f]

Suspend the current shell. Often used to stop an su command. In

ksh88, suspend is an alias for kill -STOP $$.Inksh93, it is an alias

for kill -s STOP $$. In Bash, it is a built-in command.

Options

-f Force the suspension, even if the shell is a login shell. Bash

only.

test

test condition

or

[ condition ]

or

[[ condition ]]

Evaluate a condition and, if its value is true, return a zero exit

status; otherwise, return a nonzero exit status. An alternate form of

the command uses [] rather than the word test. An additional alter-

nate form uses [[]], in which case word splitting and pathname

expansion are not done. (See the [[ ]] entry.) condition is

constructed using the following expressions. Conditions are true if

the description holds true. Features that are specific to Bash are

marked with a (B). Features that are specific to the Korn shell are

marked with a (K). Features that are specific to ksh93 are marked

with a (K93).

File Conditions

-a file

file exists.

-b file

file exists and is a block special file.

-c file

file exists and is a character special file.

-C file

file exists and is a contiguous file. This facility is not available

on most Unix systems. (K)

-d file

file exists and is a directory.

-f file

file exists and is a regular file.

-g file

file exists, ...