setenv

Synopsis

/setenv <var-name> [<value>]
/setenv -<var-name>

Description

setenv sets an environment variable in the EPIC process. The new value is inherited by processes subsequently started with exec. The hyphen form deletes the variable, so it is absent from those processes' inherited environment.

Changes do not alter the environment of EPIC's launching shell or processes already running. Programs can also replace or modify their inherited environment themselves. Changing an environment variable does not automatically repeat EPIC's startup configuration or change an internal set setting; it affects code that reads that environment variable afterward.

Arguments and effects

The first whitespace-delimited word is the variable name. Names are passed unchanged to the operating system and are case-sensitive. The remaining text becomes the value, including embedded spaces; the command does not remove quotes or interpret NAME=value assignment syntax. Use /setenv NAME value.

A name without a value sets it to an empty string. This differs from deleting it. There is no query or environment-listing form: /setenv alone prints usage. getenv can read an environment variable from a script.

A leading hyphen deletes the variable only when no value remains. If a value follows -NAME, the command instead tries to set a variable literally named -NAME; use the deletion form exactly as shown in the synopsis.

The assignment path first deletes any existing value, then calls setenv() to install the replacement. The command ignores the operating system's return codes and prints no success or failure message. Invalid names, such as names containing =, or allocation failures can prevent an assignment; an unsuccessful replacement can leave the old value deleted. The command has no script return value.

Examples

/setenv EPIC_EXAMPLE ready
/setenv EPIC_EXAMPLE a value with spaces
/setenv EPIC_EXAMPLE
/setenv -EPIC_EXAMPLE

These set a value, replace it with text containing spaces, replace it with an empty string, and finally delete the variable.

Source

Registration and setenvcmd() are in source/commands.c. Argument splitting is defined in include/words.h and implemented in source/ircaux.c and source/words.c. Child creation and program execution are in source/exec.c. The implementation calls the platform's setenv() and unsetenv() directly.