Commit 0cb98e38 authored by pw's avatar pw
Browse files

From Eric Marsden

The following patch adds a description of the *environment-list*
variable to the user manaul. It also provides an example for using the
Unix syscalls.
parent 574de697
......@@ -9893,6 +9893,20 @@ structures.
A stream connected to \file{/dev/tty}.
\end{defvar}
 
\begin{defvar}{extensions:}{environment-list}
The environment variables inherited by the current process, as a
keyword-indexed alist. For example, to access the DISPLAY
environment variable, you could use
\begin{lisp}
(cdr (assoc :display ext:*environment-list*))
\end{lisp}
Note that the case of the variable name is lost in the conversion
to a keyword.
\end{defvar}
%%\node Lisp Equivalents for C Routines, Type Translations, Useful Variables, UNIX Interface
\section{Lisp Equivalents for C Routines}
 
......@@ -10055,6 +10069,16 @@ The Unix system calls indicate an error by returning \false{} as the
first value and the Unix error number as the second value. If the call
succeeds, then the first value will always be non-\nil, often \code{t}.
 
For example, to use the \code{chdir} syscall:
\begin{lisp}
(multiple-value-bind (success errno)
(unix:unix-chdir "/tmp")
(unless success
(error "Can't change working directory: ~a"
(unix:get-unix-error-msg errno))))
\end{lisp}
\begin{defun}{Unix:}{get-unix-error-msg}{\args{\var{error}}}
 
This function returns a string describing the Unix error number
......
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