src/util.c: Add slurp(), with a simple test

1 files changed, 74 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..3d56c14
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,74 @@
+#include "config.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+#include "logerr.h"
+
+
+static const size_t
+NULL_TERMINATOR = sizeof((char)'\0');
+
+int
+slurp(const char *const filename, char **out) {
+	int rc = -1;
+
+	FILE *file = NULL;
+	char *str  = NULL;
+
+	file = fopen(filename, "r");
+	if (file == NULL) {
+		logerr("fopen(\"%s\"): %s\n", filename, strerror(errno));
+		goto out;
+	}
+
+	if (fseek(file, 0L, SEEK_END)) {
+		logerr("fseek(): %s\n", strerror(errno));
+		goto out;
+	}
+
+	const long lsize = ftell(file);
+	if (lsize == -1) {
+		logerr("ftell(): %s\n", strerror(errno));
+		goto out;
+	}
+	const size_t size = (size_t)lsize;
+
+	errno = 0;
+	rewind(file);
+	if (errno) {
+		logerr("rewind(file): %s\n", strerror(errno));
+		goto out;
+	}
+
+	str = malloc(size + NULL_TERMINATOR);
+	if (str == NULL) {
+		logerr("malloc(%ld): %s\n", size + NULL_TERMINATOR, strerror(errno));
+		goto out;
+	}
+
+	if (fread(str, sizeof(char), size, file) != size) {
+		logerr("fread(\"%s\"): %s\n", filename, strerror(errno));
+		goto out;
+	}
+	str[size] = '\0';
+	*out = str;
+
+	rc = 0;
+out:
+	if (file != NULL) {
+		if (fclose(file)) {
+			logerr("fclose(\"%s\"): %s\n", filename, strerror(errno));
+			rc = -1;
+		}
+	}
+	if (rc) {
+		if (str != NULL) {
+			free(str);
+		}
+	}
+	return rc;
+}