C: beer song

c/beer-song/src/beer_song.c

@@ -0,0 +1,44 @@
+#include "beer_song.h"
+#include <stdio.h>
+
+static char *fmt1="%s bottle%s of beer on the wall, %s bottle%s of beer.\n" \
+    "Take %s down and pass it around, %s bottle%s of beer on the wall.\n%s";
+static char *fmt2="%s bottle%s of beer on the wall, %s bottle%s of beer.\n" \
+    "%sGo to the store and buy some more, %s bottle%s of beer on the wall.\n%s";
+
+void recite(unsigned int start, unsigned int down, char *buffer)
+{
+    char n1[16], n2[16];
+    char *p=buffer;
+
+    while (down--) {
+        sprintf(n1, "%d", start);
+        sprintf(n2, "%d", start>1? start-1: 99);
+
+        p+=sprintf(p, start? fmt1: fmt2,
+                   start? n1: "No more", start==1? "": "s", start? n1: "no more",
+                   start==1? "": "s",
+                   start==1? "it": start? "one": "", start-1? n2: "no more",
+                   start==2? "": "s", down? "\n": "");
+        start=start? start-1: 99;
+    }
+}
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#ifdef UNIT_TEST
+int main(int ac, char **av)
+{
+    int arg=1;
+    unsigned i, j;
+    char buffer[1024];
+
+    for (; arg<ac-1; ++arg, ++arg) {
+        i=atoi(av[arg]);
+        j=atoi(av[arg+1]);
+        recite(i, j, buffer);
+        printf("recite(%d, %d):\n%s", i, j, buffer);
+    }
+}
+#endif

c/beer-song/src/beer_song.h

@@ -0,0 +1,18 @@
+#ifndef BEER_SONG_H
+#define BEER_SONG_H
+
+void recite(unsigned int start_bottles, unsigned int take_down, char *buffer);
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#if defined UNIT_TEST || defined DEBUG
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+#ifdef  TESTALL
+#undef  TEST_IGNORE
+#define TEST_IGNORE() {}
+#endif
+
+#endif