152 lines
5.6 KiB
HTML
152 lines
5.6 KiB
HTML
<head>
|
|
<title>arg(3) - Plan 9 from User Space</title>
|
|
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
|
|
</head>
|
|
<body bgcolor=#ffffff>
|
|
<table border=0 cellpadding=0 cellspacing=0 width=100%>
|
|
<tr height=10><td>
|
|
<tr><td width=20><td>
|
|
<tr><td width=20><td><b>ARG(3)</b><td align=right><b>ARG(3)</b>
|
|
<tr><td width=20><td colspan=2>
|
|
<br>
|
|
<p><font size=+1><b>NAME </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
ARGBEGIN, ARGEND, ARGC, ARGF, EARGF, arginit, argopt – process
|
|
option letters from argv<br>
|
|
|
|
</table>
|
|
<p><font size=+1><b>SYNOPSIS </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<tt><font size=+1>#include <u.h><br>
|
|
#include <libc.h>
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
</font></tt>
|
|
<tt><font size=+1>ARGBEGIN { <br>
|
|
char *ARGF(); <br>
|
|
char *EARGF(code); <br>
|
|
Rune ARGC(); <br>
|
|
} ARGEND <br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
</font></tt>
|
|
<tt><font size=+1>extern char *argv0; <br>
|
|
</font></tt>
|
|
</table>
|
|
<p><font size=+1><b>DESCRIPTION </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
These macros assume the names <i>argc</i> and <i>argv</i> are in scope; see
|
|
<a href="../man3/exec.html"><i>exec</i>(3)</a>. <i>ARGBEGIN</i> and <i>ARGEND</i> surround code for processing program
|
|
options. The code should be the cases of a C switch on option
|
|
characters; it is executed once for each option character. Options
|
|
end after an argument <tt><font size=+1>−−</font></tt>, before an argument <tt><font size=+1>−</font></tt>, or
|
|
before an argument that doesn’t begin with <tt><font size=+1>−</font></tt>.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
The function macro <i>ARGC</i> returns the current option character,
|
|
as an integer.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
The function macro <i>ARGF</i> returns the current option argument: a
|
|
pointer to the rest of the option string if not empty, or the
|
|
next argument in <i>argv</i> if any, or 0. <i>ARGF</i> must be called just once
|
|
for each option that takes an argument. The macro <i>EARGF</i> is like
|
|
<i>ARGF</i> but instead of returning zero runs <i>code</i> and, if that
|
|
returns, calls <a href="../man3/abort.html"><i>abort</i>(3)</a>. A typical value for <i>code</i> is <tt><font size=+1>usage()</font></tt>,
|
|
as in <tt><font size=+1>EARGF(usage())</font></tt>.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
After <i>ARGBEGIN</i>, <i>argv0</i> is a copy of <tt><font size=+1>argv[0]</font></tt> (conventionally the
|
|
name of the program).
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
After <i>ARGEND</i>, <i>argv</i> points at a zero-terminated list of the remaining
|
|
<i>argc</i> arguments.<br>
|
|
|
|
</table>
|
|
<p><font size=+1><b>EXAMPLE </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
This C program can take option <tt><font size=+1>b</font></tt> and option <tt><font size=+1>f</font></tt>, which requires
|
|
an argument.<br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<tt><font size=+1>#include <u.h><br>
|
|
#include <libc.h><br>
|
|
void<br>
|
|
main(int argc, char *argv[])<br>
|
|
{<br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
char *f;<br>
|
|
print("%s", argv[0]);<br>
|
|
ARGBEGIN {<br>
|
|
case 'b':<br>
|
|
print(" −b");<br>
|
|
break;<br>
|
|
case 'f':<br>
|
|
print(" −f(%s)", (f=ARGF())? f: "no arg");<br>
|
|
break;<br>
|
|
default:<br>
|
|
print(" badflag('%c')", ARGC());<br>
|
|
} ARGEND<br>
|
|
print(" %d args:", argc);<br>
|
|
while(*argv)<br>
|
|
print(" '%s'", *argv++);<br>
|
|
print("\n");<br>
|
|
exits(nil);<br>
|
|
|
|
</table>
|
|
}<br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
</font></tt>
|
|
|
|
</table>
|
|
Here is the output from running the command <tt><font size=+1>prog −bffile1 −r −f
|
|
file2 arg1 arg2<br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
prog −b −f(file1) badflag('r') −f(file2) 2 args: 'arg1' 'arg2'
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
</table>
|
|
</font></tt>
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
|
|
|
|
</table>
|
|
|
|
</table>
|
|
<p><font size=+1><b>SOURCE </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<tt><font size=+1>/usr/local/plan9/include/libc.h<br>
|
|
</font></tt>
|
|
</table>
|
|
|
|
<td width=20>
|
|
<tr height=20><td>
|
|
</table>
|
|
<!-- TRAILER -->
|
|
<table border=0 cellpadding=0 cellspacing=0 width=100%>
|
|
<tr height=15><td width=10><td><td width=10>
|
|
<tr><td><td>
|
|
<center>
|
|
<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
|
|
</center>
|
|
</table>
|
|
<!-- TRAILER -->
|
|
</body></html>
|