Autzoo.1269

Autzoo.1269
net.sources
utcsrgv!utzoo!henry
Mon Jan 11 15:42:39 1982
getopt(3)
The following is the source and manual page for a getopt() routine
written locally to match the description in a copy of the Unix 3.0
manual that I got to see once. Behavior is believed identical to the
Bell one, but this is NOT Bell code and carries no nondisclosure
restrictions. Use it on any system you wish.
------------
/*
* getopt - get option letter from argv
*/

#include <STDIO.H>

char *optarg; /* Global argument pointer. */
int optind = 0; /* Global argv index. */

static char *scan = NULL; /* Private scan pointer. */

extern char *index();

int
getopt(argc, argv, optstring)
int argc;
char *argv[];
char *optstring;
{
register char c;
register char *place;

optarg = NULL;

if (scan == NULL || *scan == '\0') {
if (optind == 0)
optind++;

if (optind >= argc || argv[optind][0] != '-' || argv[optind][1] == '\0')
return(EOF);
if (strcmp(argv[optind], "--")==0) {
optind++;
return(EOF);
}

scan = argv[optind]+1;
optind++;
}

c = *scan++;
place = index(optstring, c);

if (place == NULL || c == ':') {
fprintf(stderr, "%s: unknown option -%c\n", argv[0], c);
return('?');
}

place++;
if (*place == ':') {
if (*scan != '\0') {
optarg = scan;
scan = NULL;
} else {
optarg = argv[optind];
optind++;
}
}

return(c);
}
------------
TH GETOPT 3 local
DA 28 Oct 1981
SH NAME
getopt \- get option letter from argv
SH SYNOPSIS
ft B
int getopt(argc, argv, optstring)
br
int argc;
br
char **argv;
br
char *optstring;
sp
extern char *optarg;
br
extern int optind;
ft
SH DESCRIPTION
I Getopt
returns the next option letter in
I argv
that matches a letter in
IR optstring .
I Optstring
is a string of recognized option letters;
if a letter is followed by a colon, the option is expected to have
an argument that may or may not be separated from it by white space.
I Optarg
is set to point to the start of the option argument on return from
IR getopt .
PP
I Getopt
places in
I optind
the
I argv
index of the next argument to be processed.
Because
I optind
is external, it is normally initialized to zero automatically
before the first call to
IR getopt .
PP
When all options have been processed (i.e., up to the first
non-option argument),
I getopt
returns
BR EOF .
The special option
B \-\-
may be used to delimit the end of the options;
B EOF
will be returned, and
B \-\-
will be skipped.
SH SEE ALSO
getopt(1)
SH DIAGNOSTICS
I Getopt
prints an error message on
I stderr
and returns a question mark
RB ( ? )
when it encounters an option letter not included in
IR optstring .
SH EXAMPLE
The following code fragment shows how one might process the arguments
for a command that can take the mutually exclusive options
B a
and
BR b ,
and the options
B f
and
BR o ,
both of which require arguments:
PP
RS
nf
main(argc, argv)
int argc;
char **argv;
{
int c;
extern int optind;
extern char *optarg;
\&.
\&.
\&.
while ((c = getopt(argc, argv, "abf:o:")) != EOF)
switch (c) {
case 'a':
if (bflg)
errflg++;
else
aflg++;
break;
case 'b':
if (aflg)
errflg++;
else
bproc();
break;
case 'f':
ifile = optarg;
break;
case 'o':
ofile = optarg;
break;
case '?':
errflg++;
}
if (errflg) {
fprintf(stderr, "Usage: ...");
exit(2);
}
for (; optind
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The Usenet Oldnews Archive: Compilation Copyright&copy 1981, 1996
 Bruce Jones, Henry Spencer, David Wiseman.

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article may be copied and distributed freely, provided:

1. There is no money collected for the text(s) of the articles.

2. The following notice remains appended to each copy:

The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996
Bruce Jones, Henry Spencer, David Wiseman.