ubgpsuite/lonetix/argv.c

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2021-06-07 16:55:13 +02:00
// SPDX-License-Identifier: LGPL-3.0-or-later
/**
* \file argv.c
*
* Portable command line argument parsing implementation.
*
* \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
* \author Lorenzo Cogotti
*/
#include "argv.h"
#include "sys/con.h"
#include "utf/utf.h"
#include <assert.h>
#include <stdlib.h> // for getenv() on __GNUC__
#include <string.h>
const char *com_progName = NULL;
const char *com_synopsis = NULL;
const char *com_shortDescr = NULL;
const char *com_longDescr = NULL;
#define OPT_ISLONLY(flag) ((flag)->opt == '-')
#define OPT_HASLONGNAM(flag) ((flag)->longopt != NULL)
#define OPT_ARGNAME(flag) (((flag)->argName) ? (flag)->argName : "arg")
static void PrintHelpMessage(const char *prog, const Optflag *options)
{
if (!prog)
return; // quiet parsing
Sys_Printf(STDOUT, "Usage: %s", prog);
if (com_synopsis)
Sys_Printf(STDOUT, " %s", com_synopsis);
Sys_Print(STDOUT, "\n");
if (com_shortDescr)
Sys_Printf(STDOUT, "%s\n", com_shortDescr);
if (com_longDescr)
Sys_Printf(STDOUT, "\n%s\n\n", com_longDescr);
char buf[MAXUTF + 1];
size_t n;
for (const Optflag *flag = options; flag->opt != '\0'; flag++) {
Sys_Print(STDOUT, " ");
// Single char option name
if (OPT_ISLONLY(flag)) {
// Long option only, leave 2 chars for alignment purposes
assert(flag->longopt);
Sys_Print(STDOUT, " ");
} else {
// Write down single-char option first
n = runetochar(buf, flag->opt);
buf[n] = '\0';
Sys_Printf(STDOUT, "-%s", buf);
}
// Long name and (optional) argument
if (flag->longopt) {
// Write comma if necessary, or leave 2 spaces for alignment
Sys_Print(STDOUT, OPT_ISLONLY(flag) ? " " : ", ");
Sys_Printf(STDOUT, "--%s", flag->longopt);
// Append argument with a leading = sign
switch (flag->hasArg) {
default: assert(FALSE); break;
case ARG_NONE: break;
case ARG_OPT: Sys_Printf(STDOUT, "[=%s]", OPT_ARGNAME(flag)); break;
case ARG_REQ: Sys_Printf(STDOUT, "=%s", OPT_ARGNAME(flag)); break;
}
} else {
// Output argument, short options have no leading =
switch (flag->hasArg) {
default: assert(FALSE); break;
case ARG_NONE: break;
case ARG_OPT: Sys_Printf(STDOUT, " [%s]", OPT_ARGNAME(flag)); break;
case ARG_REQ: Sys_Printf(STDOUT, " <%s>", OPT_ARGNAME(flag)); break;
}
}
if (flag->descr)
Sys_Printf(STDOUT, "\t%s", flag->descr);
Sys_Print(STDOUT, "\n");
}
// Append help options
Sys_Print(STDOUT, " -h, --help\tPrint this help message\n");
Sys_Print(STDOUT, " -?\tEquivalent to -h\n");
}
// If `prog` is not NULL, output an excess argument error (only called for long options).
static void PrintExcessArgError(const char *prog,
const Optflag *flag,
const char *arg)
{
if (!prog)
return; // quiet parse
assert(flag->longopt);
Sys_Printf(STDERR, "%s: Option --%s takes no argument: --%s=%s", prog, flag->longopt, flag->longopt, arg);
}
static void PrintMissingArgError(const char *prog, const Optflag *flag, Boolean longName)
{
if (!prog)
return; // quiet parse
char buf[MAXUTF+1];
const char *nam = NULL;
const char *pfx = (longName) ? "--" : "-";
if (longName)
nam = flag->longopt;
else {
size_t n = runetochar(buf, flag->opt);
buf[n] = '\0';
nam = buf;
}
Sys_Printf(STDERR, "%s: Option", prog);
if (nam)
Sys_Printf(STDERR, " %s%s", pfx, nam);
Sys_Print(STDERR, " requires mandatory argument");
if (flag->argName)
Sys_Printf(STDERR, " <%s>", flag->argName);
Sys_Printf(STDERR, ": %s%s\n", pfx, nam);
}
CHECK_PRINTF(2, 0) static void PrintBadCmdLineError(const char *prog,
const char *fmt,
...)
{
if (!prog)
return; // quiet parsing
va_list va;
va_start(va, fmt);
Sys_Printf(STDERR, "%s: ", prog);
Sys_VPrintf(STDERR, fmt, va);
Sys_Print(STDERR, "\n");
va_end(va);
}
static Optflag *FindLongFlag(const char *p, char **optarg, const char *prog, Optflag *options)
{
char *arg = strchr(p, '=');
*optarg = arg;
char *name;
if (arg) {
size_t n = arg - p;
name = (char *) alloca(n + 1);
memcpy(name, p, n);
name[n] = '\0';
} else
name = (char *) p; // safe
for (Optflag *flag = options; flag->opt != '\0'; flag++) {
if (OPT_HASLONGNAM(flag) && strcmp(flag->longopt, name) == 0) {
flag->flagged = TRUE;
return flag;
}
}
if (prog)
Sys_Printf(STDERR, "%s: Unrecognized option: --%s\n", prog, name);
return NULL;
}
static Optflag *FindFlag(Rune r, const char *prog, Optflag *flags)
{
for (Optflag *flag = flags; flag->opt != '\0'; flag++) {
// NOTE: options with long names are skipped (-- is end of argument list)
if (flag->opt == r) {
flag->flagged = TRUE;
return flag;
}
}
if (prog) {
char buf[MAXUTF + 1];
size_t n = runetochar(buf, r);
buf[n] = '\0';
Sys_Printf(STDERR, "%s: Unrecognized option: -%s\n", prog, buf);
}
return NULL;
}
#ifdef __GNUC__
static void ReorderArgv(int argc, char **argv, const Optflag *options)
{
if (getenv("POSIXLY_CORRECT"))
return; // don't mess with argv is POSIX behavior is requested
USED(argc); USED(argv); USED(options);
// TODO
}
#endif
int Com_ArgParse(int argc, char **argv, Optflag *options, unsigned flags)
{
Optflag *flag;
char *p, *optarg;
// Initial setup
char *prog = NULL; // FindFlag*() functions won't log on NULL `prog`
if ((flags & ARG_QUIET) == 0) {
// Extract program name, so parsing outputs meaningful messages
prog = (char *) com_progName;
if (!prog) {
// Generate from argv[0]
prog = argv[0]; // TODO: basename(argv[0]);
}
}
#ifdef __GNUC__
/* GNU allows program options in any order with respect to program
* arguments, for example:
* ```c
* program file -cv
* ```
* According to POSIX both `file` and `-cv` are program arguments.
* According to GNU `-cv` are options, `file` is a program argument.
*
* To do this GNU getopt() implicitly reorders `argv`.
*/
if ((flags & ARG_NOREORD) == 0)
ReorderArgv(argc, argv, options);
#endif
// Parse argument list
int optind;
for (optind = 1; optind < argc; optind++) {
p = argv[optind];
if (strcmp(p, "--") == 0) {
optind++;
break; // explicit end of command list
}
if (p[0] == '-' && p[1] == '-') {
// GNU style long option
p += 2;
if (strcmp(p, "help") == 0) {
PrintHelpMessage(prog, options);
return OPT_HELP;
}
flag = FindLongFlag(p, &optarg, prog, options);
if (!flag)
return OPT_UNKNOWN;
if (!optarg && flag->hasArg)
optarg = argv[++optind]; // fetch argument from `argv`
if (optarg && flag->hasArg == ARG_NONE) {
PrintExcessArgError(prog, flag, optarg);
return OPT_EXCESSARG;
}
if (!optarg && flag->hasArg == ARG_REQ) {
PrintMissingArgError(prog, flag, /*longName=*/TRUE);
return OPT_ARGMISS;
}
flag->optarg = optarg;
} else if (p[0] == '-' && p[1] != '\0') {
// Unix-style single char option
p++;
do {
Rune r;
p += chartorune(&r, p);
if (r == '-') {
/* This can happen in events like: -a-c
* where a->hasArg == ARG_NONE
*
* There is no way to fix this ambiguity safely:
* * if -c is an argument to -a then it is OPT_EXCESSARG error
* * if -a -- -c problematic because it's counterintuitive
* for the user
* (one could get surprising -c program arguments)
* * if we take it as -a --(force as option) -c it would be
* dangerous (sometimes -- is an option, sometimes an
* end of option list)
*
* NOTE: getopt() appears to do the last, and it's
* horrific
*/
PrintBadCmdLineError(prog, "Ambiguous '-' in short options list: %s", argv[optind]);
return OPT_BADARGV;
}
// Handle single char help requests
if (r == '?' || r == 'h') {
PrintHelpMessage(prog, options);
return OPT_HELP;
}
flag = FindFlag(r, prog, options);
if (!flag)
return OPT_UNKNOWN;
optarg = NULL;
if (flag->hasArg)
optarg = (*p != '\0') ? p : argv[++optind];
if (!optarg && flag->hasArg == ARG_REQ) {
PrintMissingArgError(prog, flag, /*longName=*/FALSE);
return OPT_ARGMISS;
}
flag->optarg = optarg;
} while (*p != '\0');
}
#if 0 && defined(_WIN32) // TODO
else if (p[0] == '/' && p[1] != '\0') {
// DOS style option
}
#endif
else {
// End of argument list, break the loop
break;
}
}
return optind;
}