Go to the first, previous, next, last section, table of contents.
Shell functions are defined with the function reserved word or the
special syntax `funcname ()'.
Shell functions are read in and stored internally. Alias names are
resolved when the function is read. Functions are executed like
commands with the arguments passed as positional parameters.
Functions execute in the same process as the caller and share all files
and the present working directory with the caller. A trap on
EXIT set inside a function is executed after the function
completes in the environment of the caller.
The return builtin is used to return from function calls.
Function identifiers can be listed with the functions builtin.
Functions can be undefined with the unfunction builtin.
The following functions, if defined, have special meaning to the shell:
chpwd
precmd
preexec
periodic
PERIOD is set, this function is executed every
PERIOD seconds, just before a prompt.
TRAPxxx
SIGxxx, where xxx is a signal
name as specified for the kill builtin (see section Shell Builtin Commands). In addition, TRAPZERR is executed whenever a command
has a non-zero exit status, TRAPDEBUG is executed after each
command, and TRAPEXIT is executed when the shell exits, or when
the current function exits if defined inside a function. If a function
of this form is defined and null, the shell and processes spawned by it
will ignore SIGxxx.
Go to the first, previous, next, last section, table of contents.