1 files changed, 39 insertions, 0 deletions
diff --git a/io.c b/io.c
index 98afe53..063265b 100644
--- a/io.c
+++ b/io.c
@@ -2,6 +2,45 @@
 #include "common.h"
 
 
+char *
+readtextfileat(int dfd, const char *path)
+{
+	int fd;
+	char *text = NULL;
+	size_t size = 0;
+	size_t len = 0;
+	ssize_t r;
+
+	fd = openat(dfd, path, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+
+	for (;;) {
+		if (len == size) {
+			size = size ? size * 2U : 64U;
+			text = erealloc(text, size);
+		}
+		r = read(fd, &text[len], size - len);
+		if (r <= 0) {
+			if (!r)
+				break;
+			if (errno == EINTR)
+				continue;
+			close(fd);
+			return NULL;
+		}
+		len += (size_t)r;
+	}
+
+	close(fd);
+
+	if (len == size)
+		text = erealloc(text, len + 1U);
+	text[len] = '\0';
+	return text;
+}
+
+
 void
 writeall(int fd, const void *data, size_t n, const char *fname)
 {