jbc@mcc-db.UUCP (John B. Chambers) (07/15/85)
From: John Chambers (guest moderator) <ut-sally!std-unix>
Topic: getopt and command line arguments continued
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Date: Wed, 10 Jul 85 15:14:05 edt
From: harvard!talcott!wjh12!mirror!rs@ut-sally.ARPA (Rich Salz)
Subject: Re; bostic's getopt
I have modified Keith Bostic's getopt code to make three changes:
1. my own (warped) esthetics.
2. add non-stdio code compile-time flag.
3. add trivial code to handle the opterr variable.
This last change is the most important; opterr, if set to 0 in
mainline code, suppresses printing all error messages.
i also cleaned up a couple of things.
feel free to re-post this to std-unix, or even {net,mod}.sourceds
if you think it will be worthwhile...
--
Rich $alz {mit-eddie, ihnp4!inmet, wjh12, cca, datacube} !mirror!rs
Mirror Systems 2067 Massachusetts Ave.
617-661-0777 Cambridge, MA, 02140
/*
** This is a public domain version of getopt(3).
** Bugs, fixes to:
** Keith Bostic
** ARPA: keith@seismo
** UUCP: seismo!keith
** Added NO_STDIO, opterr handling, Rich $alz (mirror!rs).
*/
#include <stdio.h>
/*
** Error macro. Maybe we want stdio, maybe we don't.
** The (undocumented?) variable opterr tells us whether or not
** to print errors.
*/
#ifdef NO_STDIO
#define tell(s) \
if (opterr) \
{ \
char ebuf[2]; \
(void)write(2, nargv, (unsigned int)strlen(nargv)); \
(void)write(2, s, (unsigned int)strlen(s)); \
ebuf[0] = optopt; \
ebuf[1] = '\n'; \
(void)write(2, ebuf, 2); \
}
#else
#define tell(s) \
if (opterr) \
(void)fputs(*nargv, stderr), \
(void)fputs(s,stderr), \
(void)fputc(optopt, stderr), \
(void)fputc('\n', stderr)
#endif
/* Global variables. */
static char EMSG[] = "";
int opterr = 1; /* undocumented error-suppressor*/
int optind = 1, /* index into argv vector */
int optopt; /* char checked for validity */
char *optarg; /* arg associated with option */
/* Linked in later. */
extern char *index(); /* This may be strchr */
getopt(nargc, nargv, ostr)
int nargc;
char **nargv;
char *ostr;
{
static char *place = EMSG; /* option letter processing */
register char *oli; /* option letter list index */
if (!*place) /* update scanning pointer */
{
if (optind >= nargc || *(place = nargv[optind]) != '-' || !*++place)
return(EOF);
if (*place == '-') /* found "--" */
{
optind++;
return(EOF);
}
}
/* option letter okay? */
if ((optopt = *place++) == ':' || (oli = index(ostr, optopt)) == NULL)
{
if (!*place)
optind++;
tell(": illegal option -- ");
goto Bad;
}
if (*++oli != ':') /* don't need argument */
{
optarg = NULL;
if (!*place)
optind++;
}
else /* need an argument */
{
if (*place)
optarg = place; /* no white space */
else
if (nargc <= ++optind)
{
place = EMSG;
tell(": option requires an argument -- ");
goto Bad;
}
else
optarg = nargv[optind]; /* white space */
place = EMSG;
optind++;
}
return(optopt); /* dump back option letter */
Bad:
return('?');
}
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--
John B. Chambers, Microelectronics and Computer Technology Corp., Austin, TX
{ihnp4,seismo,ctvax}!ut-sally!mcc-db!jbc, jbc@ut-sally.ARPA, chambers@mcc.ARPA