Tinkering with function pointers

3 files changed, 53 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d547342
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+funcptr
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..74fe256
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,9 @@
+.PHONY: all clean
+
+CC = clang
+CFLAGS = -std=c90 -Weverything
+
+all : funcptr
+
+clean :
+	rm -f funcptr
diff --git a/funcptr.c b/funcptr.c
new file mode 100644
index 0000000..de77066
--- /dev/null
+++ b/funcptr.c
@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int doub(int);
+int trip(int);
+int half(int);
+void fpv_exec(int (**fpv)(int), int n);
+
+int doub(int i) {
+    return i * 2;
+}
+
+int trip(int i) {
+    return i * 3;
+}
+
+int half(int i) {
+    return i / 2;
+}
+
+void fpv_exec(int (**fpv)(int), int n) {
+    int i;
+    for (i = 0; *(fpv + i) != NULL; i++) {
+        printf("%d\n", (*(fpv + i))(n));
+    }
+}
+
+int main(int argc, char **argv) {
+    int (**fpv)(int);
+    fpv = calloc(4, sizeof(int (*)(int)));
+
+    fpv[0] = doub;
+    fpv[1] = trip;
+    fpv[2] = half;
+    fpv[3] = NULL;
+
+    for (argv++, argc--; argc; argv++, argc--) {
+        fpv_exec(fpv, atoi(*argv));
+    }
+
+    exit(EXIT_SUCCESS);
+}
+