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doc: run-program: add limitations section

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Signed-off-by: Daniel Kochmański <daniel@turtleware.eu>
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Daniel Kochmański 2015-08-09 11:38:01 +02:00
parent 060a7e22eb
commit decd57bd3d
1 changed files with 24 additions and 11 deletions
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35
doc/ref_os.xmlf
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@ -362,9 +362,9 @@ ls [--help | -?] filename*
</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>
@ -408,7 +408,8 @@ ls [--help | -?] filename*
<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 (&amp;optional (file "/etc/passwd"))
<programlisting>
(defun all-users (&amp;optional (file "/etc/passwd"))
(let ((s (ext:run-program "sed"
(list "-e" "/^#.*$/d;/^[^:]*$/d;s,^\\([^:]*\\).*$,\\1,g"
file)
@ -417,19 +418,31 @@ ls [--help | -?] filename*
(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>