--- /dev/null
+/* Actual code to parse commandline. */
+#include <ccan/opt/opt.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "private.h"
+
+/* glibc does this as:
+/tmp/opt-example: invalid option -- 'x'
+/tmp/opt-example: unrecognized option '--long'
+/tmp/opt-example: option '--someflag' doesn't allow an argument
+/tmp/opt-example: option '--s' is ambiguous
+/tmp/opt-example: option requires an argument -- 's'
+*/
+static int parse_err(void (*errlog)(const char *fmt, ...),
+ const char *argv0, const char *arg, unsigned len,
+ const char *problem)
+{
+ errlog("%s: %.*s: %s", argv0, len, arg, problem);
+ return -1;
+}
+
+static void consume_option(int *argc, char *argv[], unsigned optnum)
+{
+ memmove(&argv[optnum], &argv[optnum+1],
+ sizeof(argv[optnum]) * (*argc-optnum));
+ (*argc)--;
+}
+
+/* Returns 1 if argument consumed, 0 if all done, -1 on error. */
+int parse_one(int *argc, char *argv[], unsigned *offset,
+ void (*errlog)(const char *fmt, ...))
+{
+ unsigned i, arg, len;
+ const char *o, *optarg = NULL;
+ char *problem;
+
+ if (getenv("POSIXLY_CORRECT")) {
+ /* Don't find options after non-options. */
+ arg = 1;
+ } else {
+ for (arg = 1; argv[arg]; arg++) {
+ if (argv[arg][0] == '-')
+ break;
+ }
+ }
+
+ if (!argv[arg] || argv[arg][0] != '-')
+ return 0;
+
+ /* Special arg terminator option. */
+ if (strcmp(argv[arg], "--") == 0) {
+ consume_option(argc, argv, arg);
+ return 0;
+ }
+
+ /* Long options start with -- */
+ if (argv[arg][1] == '-') {
+ assert(*offset == 0);
+ for (o = first_lopt(&i, &len); o; o = next_lopt(o, &i, &len)) {
+ if (strncmp(argv[arg] + 2, o, len) != 0)
+ continue;
+ if (argv[arg][2 + len] == '=')
+ optarg = argv[arg] + 2 + len + 1;
+ else if (argv[arg][2 + len] != '\0')
+ continue;
+ break;
+ }
+ if (!o)
+ return parse_err(errlog, argv[0],
+ argv[arg], strlen(argv[arg]),
+ "unrecognized option");
+ /* For error messages, we include the leading '--' */
+ o -= 2;
+ len += 2;
+ } else {
+ /* offset allows us to handle -abc */
+ for (o = first_sopt(&i); o; o = next_sopt(o, &i)) {
+ if (argv[arg][*offset + 1] != *o)
+ continue;
+ (*offset)++;
+ break;
+ }
+ if (!o)
+ return parse_err(errlog, argv[0],
+ argv[arg], strlen(argv[arg]),
+ "unrecognized option");
+ /* For error messages, we include the leading '-' */
+ o--;
+ len = 2;
+ }
+
+ if (opt_table[i].type == OPT_NOARG) {
+ if (optarg)
+ return parse_err(errlog, argv[0], o, len,
+ "doesn't allow an argument");
+ problem = opt_table[i].cb(opt_table[i].arg);
+ } else {
+ if (!optarg) {
+ /* Swallow any short options as optarg, eg -afile */
+ if (*offset && argv[arg][*offset + 1]) {
+ optarg = argv[arg] + *offset + 1;
+ *offset = 0;
+ } else
+ optarg = argv[arg+1];
+ }
+ if (!optarg)
+ return parse_err(errlog, argv[0], o, len,
+ "requires an argument");
+ problem = opt_table[i].cb_arg(optarg, opt_table[i].arg);
+ }
+
+ if (problem) {
+ parse_err(errlog, argv[0], o, len, problem);
+ free(problem);
+ return -1;
+ }
+
+ /* If no more letters in that short opt, reset offset. */
+ if (*offset && !argv[arg][*offset + 1])
+ *offset = 0;
+
+ /* All finished with that option? */
+ if (*offset == 0) {
+ consume_option(argc, argv, arg);
+ if (optarg && optarg == argv[arg])
+ consume_option(argc, argv, arg);
+ }
+ return 1;
+}