</varlistentry>
<varlistentry>
<term><replaceable>error</replaceable></term>
- <listitem><para>One of <symbol>:OUTPUT</symbol>, <symbol>T</symbol> or
- <symbol>NIL</symbol>, defaults to
- <symbol>T</symbol></para></listitem>
+ <listitem><para>One of <symbol>:OUTPUT</symbol>, <symbol>:STREAM</symbol>,
+ <symbol>T</symbol> or <symbol>NIL</symbol>, defaults to
+ <symbol>:OUTPUT</symbol></para></listitem>
</varlistentry>
</variablelist>
</refsynopsisdiv>
<para>List all users in a Unix system. We use the <command>sed</command>
command to parse the file with the list of users, removing comments and
information other than the user names:
-<programlisting>(defun all-users (&optional (file "/etc/passwd"))
+ <programlisting>
+(defun all-users (&optional (file "/etc/passwd"))
(let ((s (ext:run-program "sed"
(list "-e" "/^#.*$/d;/^[^:]*$/d;s,^\\([^:]*\\).*$,\\1,g"
file)
(error "Unable to parse password file"))
(loop for x = (read s NIL NIL)
while x
- collect x)))</programlisting></para>
+ collect x)))
+ </programlisting></para>
<para>Make a directory. Redirect standard error output to the same as the
output:
-<programlisting>(ext:run-program "mkdir" '("./tmp") :output :STREAM :error :OUTPUT)
-</programlisting>
-</para>
+
<programlisting>(ext:run-program "mkdir" '("./tmp") :output :STREAM :error :OUTPUT)
+ </programlisting>
+ </para>
<para>Same as before, but now both the output and the standard error are
discarded
-<programlisting>(ext:run-program "mkdir" '("./tmp") :output NIL :error :OUTPUT)
-</programlisting>
-</para>
+ <programlisting>(ext:run-program "mkdir" '("./tmp") :output NIL :error :OUTPUT)
+ </programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Limitations</title>
+
+ <para>All streams passed to <function>ext:run-program</function> has to have
+ underlying file handler. That means, that if gray streams are passed to
+ function - it might signal an error. Such situation might occur, for
+ instance, if <symbol>output</symbol> value is <symbol>T</symbol> and
+ <symbol>*standard-output*</symbol> is bound to gray stream (default if using
+ slime and emacs).</para>
</refsect1>
</refentry>
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