GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  ARG (3)

NAME

ARGBEGIN, ARGEND, ARGC, ARGF, EARGF, arginit, argopt - process option letters from argv

CONTENTS

Synopsis
Description
Example
Source

SYNOPSIS

#include <u.h>
#include <libc.h>


ARGBEGIN { 

char *ARGF(); 

char *EARGF(code); 

Rune ARGC(); 

} ARGEND 

extern char *argv0;

DESCRIPTION

These macros assume the names argc and argv are in scope; see exec(3). ARGBEGIN and ARGEND 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 --, before an argument -, or before an argument that doesn’t begin with -.

The function macro ARGC returns the current option character, as an integer.

The function macro ARGF returns the current option argument: a pointer to the rest of the option string if not empty, or the next argument in argv if any, or 0. ARGF must be called just once for each option that takes an argument. The macro EARGF is like ARGF but instead of returning zero runs code and, if that returns, calls abort(3). A typical value for code is usage(), as in EARGF(usage()).

After ARGBEGIN, argv0 is a copy of argv[0] (conventionally the name of the program).

After ARGEND, argv points at a zero-terminated list of the remaining argc arguments.

EXAMPLE

This C program can take option b and option f, which requires an argument.
#include <u.h> #include <libc.h> void main(int argc, char *argv[]) {
        char *f;
        print("%s", argv[0]);
        ARGBEGIN {
        case ’b’:
                print(" -b");
                break;
        case ’f’:
                print(" -f(%s)", (f=ARGF())? f: "no arg");
                break;
        default:
                print(" badflag(’%c’)", ARGC());
        } ARGEND
        print(" %d args:", argc);
        while(*argv)
                print(" ’%s’", *argv++);
        print("\n");
        exits(nil); }
Here is the output from running the command prog -bffile1 -r -f file2 arg1 arg2
prog -b -f(file1) badflag(’r’) -f(file2) 2 args: ’arg1’ ’arg2’

SOURCE

/usr/local/plan9/include/libc.h
Search for    or go to Top of page |  Section 3 |  Main Index


ARG (3) -->

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.