From 78e51a8c6678b6e3dff3d619aa786669f531f4bc Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 03:45:44 +0000 Subject: checkpoint --- man/man3/arg.html | 152 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 man/man3/arg.html (limited to 'man/man3/arg.html') diff --git a/man/man3/arg.html b/man/man3/arg.html new file mode 100644 index 00000000..8ca66c80 --- /dev/null +++ b/man/man3/arg.html @@ -0,0 +1,152 @@ + +arg(3) - Plan 9 from User Space + + + + +
+
+
ARG(3)ARG(3) +
+
+

NAME
+ +
+ + ARGBEGIN, ARGEND, ARGC, ARGF, EARGF, arginit, argopt – process + option letters from argv
+ +
+

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
+ +
+ +

 +
+
+ + +
+
+
+Space Glenda +
+
+ + -- cgit v1.2.3