readstring function

1 files changed, 14 insertions, 1 deletions

diff --git a/lib.c b/lib.c
index 9660003..137b1bd 100644
--- a/lib.c
+++ b/lib.c
@@ -40,7 +40,19 @@ static Val fn_writebytes(State *S, int nargs, Val *args) {
 	return VAL_NIL;
 }
 
-
+static Val fn_readstring(State *S, int nargs, Val *args){
+	CHECK(nargs == 1, "need exactly 1 arg to readstring");
+	CHECK(IS_STRING(args[0]), "need string arg to readstring");
+	FILE *f = fopen(AS_CSTRING(args[0]), "r");
+	CHECK(f != NULL, "io error (fopen)");
+	fseek(f, 0L, SEEK_END);
+	long flen = ftell(f);
+	char *buf = NEW_ARR(S, char, flen+1);
+	rewind(f); fread(buf, 1, flen, f);
+		CHECK(!ferror(f), "file error");
+	buf[flen] = '\0';
+	return VAL_OBJ(objstring_take(S, buf, flen));
+}
 
 
 // lists
@@ -158,6 +170,7 @@ static BuiltinFunc builtin_funcs[] = {
 	{ "say", fn_say },
 	{ "write", fn_write },
 	{ "writebytes", fn_writebytes },
+	{ "readstring", fn_readstring },
 
 	{ "arr", fn_arr },
 	{ "append!", fn_append },