Second commit

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 66 insertions, 0 deletions

diff --git a/open.c b/open.c
new file mode 100644
index 0000000..8d1a4c5
--- /dev/null
+++ b/open.c
@@ -0,0 +1,66 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+int
+patheq(const char *have, const char *want, const char **end_out)
+{
+	while (*want) {
+		if (*have != *want)
+			return 0;
+		if (*have == '/') {
+			while (*++have == '/');
+			while (*++want == '/');
+		}
+	}
+	if (!end_out)
+		return !*have;
+	*end_out = have;
+	return 1;
+}
+
+
+int
+openfile(const char *path, int *is_new_fd_out, const char **fname_out)
+{
+	const char *p;
+	int fd, digit;
+
+	*fname_out = path;
+
+	if (patheq(path, "/dev/fd/", &p) || patheq(path, "/proc/self/fd/", &p)) {
+		fd = 0;
+		while (isdigit(*p)) {
+			digit = (int)(*p & 15);
+			if (fd > (INT_MAX - digit) / 10)
+				goto fallback;
+			fd = fd * 10 + digit;
+		}
+		if (*p)
+			goto fallback;
+		*is_new_fd_out = 0;
+		return 0;
+	} else if (!strcmp(path, "-")) {
+		*fname_out = "<stdin>";
+		*is_new_fd_out = 0;
+		return STDIN_FILENO;
+	} else if (patheq(path, "/dev/stdin", NULL)) {
+		*is_new_fd_out = 0;
+		return STDIN_FILENO;
+	} else if (patheq(path, "/dev/stdout", NULL)) {
+		*is_new_fd_out = 0;
+		return STDOUT_FILENO;
+	} else if (patheq(path, "/dev/stderr", NULL)) {
+		*is_new_fd_out = 0;
+		return STDERR_FILENO;
+	} else {
+	fallback:
+		fd = open(path, O_RDONLY);
+		if (fd < 0) {
+			weprintf("%s:", path);
+			return -1;
+		}
+		*is_new_fd_out = 0;
+		return fd;
+	}
+}