Add and use a common readfile() function

This function is used to read the full content of a textfile into a
newly allocated buffer (with zerotermination).

It replaces the earlier readfile() in scan-tree.c (which was rather
error-prone[1]), and is reused by read_agefile() in ui-repolist.c.

1: No checks for EINTR and EAGAIN, fixed-size buffer

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/shared.c b/shared.c
index 911a55a..4cb9573 100644
--- a/shared.c
+++ b/shared.c
@@ -372,24 +372,45 @@ int cgit_open_filter(struct cgit_filter *filter)
 			"Unable to use pipe as STDIN");
 		execvp(filter->cmd, filter->argv);
 		die("Unable to exec subprocess %s: %s (%d)", filter->cmd,
 			strerror(errno), errno);
 	}
 	close(filter->pipe_fh[0]);
 	chk_non_negative(dup2(filter->pipe_fh[1], STDOUT_FILENO),
 		"Unable to use pipe as STDOUT");
 	close(filter->pipe_fh[1]);
 	return 0;
 }
 
 int cgit_close_filter(struct cgit_filter *filter)
 {
 	chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
 		"Unable to restore STDOUT");
 	close(filter->old_stdout);
 	if (filter->pid < 0)
 		return 0;
 	waitpid(filter->pid, &filter->exitstatus, 0);
 	if (WIFEXITED(filter->exitstatus) && !WEXITSTATUS(filter->exitstatus))
 		return 0;
 	die("Subprocess %s exited abnormally", filter->cmd);
 }
+
+/* Read the content of the specified file into a newly allocated buffer,
+ * zeroterminate the buffer and return 0 on success, errno otherwise.
+ */
+int readfile(const char *path, char **buf, size_t *size)
+{
+	int fd;
+	struct stat st;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		return errno;
+	if (fstat(fd, &st))
+		return errno;
+	if (!S_ISREG(st.st_mode))
+		return EISDIR;
+	*buf = xmalloc(st.st_size + 1);
+	*size = read_in_full(fd, *buf, st.st_size);
+	(*buf)[*size] = '\0';
+	return (*size == st.st_size ? 0 : errno);
+}