configure: Provide a poor man's replacement for getline()

uClibc is one such library that doesn't implement getline()

Reported-by: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 51 insertions, 0 deletions

diff --git a/libobj/getline.c b/libobj/getline.c
new file mode 100644
index 00000000..5acdf8d1
--- /dev/null
+++ b/libobj/getline.c
@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+extern int getline(char **line, size_t *len, FILE *file);
+
+int getline(char **line, size_t *len, FILE *file)
+{
+	char *ptr, *end;
+	int c;
+
+	if (*line == NULL) {
+		errno = EINVAL;
+		if (*len == 0)
+			*line = malloc(4096);
+		if (*line == NULL)
+			return -1;
+
+		*len = 4096;
+	}
+
+	ptr = *line;
+	end = *line + *len;
+
+	while ((c = fgetc(file)) != EOF) {
+		if (ptr + 1 >= end) {
+			char *newline;
+			int offset;
+
+			newline = realloc(*line, *len + 4096);
+			if (newline == NULL)
+				return -1;
+
+			offset = ptr - *line;
+
+			*line = newline;
+			*len += 4096;
+
+			ptr = *line + offset;
+			end = *line + *len;
+		}
+
+		*ptr++ = c;
+		if (c == '\n') {
+			*ptr = '\0';
+			return ptr - *line;
+		}
+	}
+	*ptr = '\0';
+	return -1;
+}