add getline impl

engine/src/getline.c

@@ -0,0 +1,54 @@
+#include <GearSrc/File.h>
+
+#define GETLINE_MINSIZE 16
+
+int GSFileGetLine(char** lineptr, int* n, FILE* fp) {
+	int   ch;
+	int   i		  = 0;
+	char  free_on_err = 0;
+	char* p;
+
+	if(lineptr == NULL || n == NULL || fp == NULL) {
+		return -1;
+	}
+	if(*lineptr == NULL) {
+		*n	 = GETLINE_MINSIZE;
+		*lineptr = (char*)malloc(sizeof(char) * (*n));
+		if(*lineptr == NULL) {
+			return -1;
+		}
+		free_on_err = 1;
+	}
+
+	for(i = 0;; i++) {
+		ch = fgetc(fp);
+		while(i >= (*n) - 2) {
+			*n *= 2;
+			p = realloc(*lineptr, sizeof(char) * (*n));
+			if(p == NULL) {
+				if(free_on_err)
+					free(*lineptr);
+				return -1;
+			}
+			*lineptr = p;
+		}
+		if(ch == EOF) {
+			if(i == 0) {
+				if(free_on_err)
+					free(*lineptr);
+				return -1;
+			}
+			(*lineptr)[i] = '\0';
+			*n	      = i;
+			return i;
+		}
+
+		if(ch == '\n') {
+			(*lineptr)[i]	  = '\n';
+			(*lineptr)[i + 1] = '\0';
+			*n		  = i + 1;
+			return i + 1;
+		}
+		(*lineptr)[i] = (char)ch;
+	}
+}