Finally getting around to playing with getopt in C

digressions/.gitignore

@@ -1,2 +1,3 @@
 /temperatures
 /qsort-example
+/getopt-example

digressions/Makefile

@@ -3,6 +3,6 @@ CFLAGS += -g -Wall -Wextra -pedantic -pedantic-errors
 %.class:%.java
 	javac -d $(PWD) $^
 
-all: temperatures qsort-example URLParts.class
+all: temperatures qsort-example getopt-example URLParts.class
 
 .PHONY: all

digressions/getopt-example.c

@@ -0,0 +1,45 @@
+/*
+ * Example getopt usage mostly from getopt(3)
+ */
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int
+main(int argc, char *argv[])
+{
+    int flags, opt;
+    int nsecs, tfnd;
+
+    nsecs = 0;
+    tfnd = 0;
+    flags = 0;
+    while ((opt = getopt(argc, argv, "nt:")) != -1) {
+        switch (opt) {
+        case 'n':
+            flags = 1;
+            break;
+        case 't':
+            nsecs = atoi(optarg);
+            tfnd = 1;
+            break;
+        default: /* '?' */
+            fprintf(stderr, "Usage: %s [-t nsecs] [-n] name\n",
+                    argv[0]);
+            exit(EXIT_FAILURE);
+        }
+    }
+
+    printf("flags=%d; tfnd=%d; optind=%d\n", flags, tfnd, optind);
+
+    if (optind >= argc) {
+        fprintf(stderr, "Expected argument after options\n");
+        exit(EXIT_FAILURE);
+    }
+
+    printf("name argument = %s\n", argv[optind]);
+
+    /* Other code omitted */
+
+    exit(EXIT_SUCCESS);
+}