add program module

src/program.c

@@ -0,0 +1,45 @@
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include "program.h"
+
+int program_loadfromfile(struct program *prog, const char *filename) {
+
+	struct stat st;
+	ssize_t rc = -1;
+	int fd;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "Could not open file %s: %s\n",
+			filename, strerror(errno));
+		return -1;
+	}
+
+	if (fstat(fd, &st) < 0)
+		goto close_fd;
+
+	prog->len = st.st_size;
+	prog->instr = malloc(prog->len);
+	if (prog->instr == NULL)
+		goto close_fd;
+
+	rc = read(fd, prog->instr, prog->len);
+	if (rc < 0)
+		goto free_mem;
+	return rc;
+free_mem: free(prog->instr);
+close_fd: close(fd);
+	return rc;
+}
+
+void program_free(struct program *prog) {
+
+	free(prog->instr);
+	prog->len = 0;
+}