tasks a-s

Task/Partial-function-application/C/partial-function-application-1.c

@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <sys/wait.h>
+#include <err.h>
+
+typedef int (*intfunc)(int);
+typedef void (*pfunc)(int*, int);
+
+pfunc partial(intfunc fin)
+{
+	pfunc f;
+	static int idx = 0;
+	char cc[256], lib[256];
+	FILE *fp;
+	sprintf(lib, "/tmp/stuff%d.so", ++idx);
+	sprintf(cc, "cc -pipe -x c -shared -o %s -", lib);
+
+	fp = popen(cc, "w");
+	fprintf(fp, "#define t typedef\xat int _i,*i;t _i(*__)(_i);__ p =(__)%p;"
+		"void _(i _1, _i l){while(--l>-1)l[_1]=p(l[_1]);}", fin);
+	fclose(fp);
+
+	*(void **)(&f) = dlsym(dlopen(lib, RTLD_LAZY), "_");
+	unlink(lib);
+	return f;
+}
+
+int square(int a)
+{
+	return a * a;
+}
+
+int dbl(int a)
+{
+	return a + a;
+}
+
+int main()
+{
+	int x[] = { 1, 2, 3, 4 };
+	int y[] = { 1, 2, 3, 4 };
+	int i;
+
+	pfunc f = partial(square);
+	pfunc g = partial(dbl);
+
+	printf("partial square:\n");
+	f(x, 4);
+	for (i = 0; i < 4; i++) printf("%d\n", x[i]);
+
+	printf("partial double:\n");
+	g(y, 4);
+	for (i = 0; i < 4; i++) printf("%d\n", y[i]);
+
+	return 0;
+}