Add build system scaffolding and libc headers

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/libc/stdio/perror.c b/lib/libc/stdio/perror.c
new file mode 100644
index 00000000..f3f4bb19
--- /dev/null
+++ b/lib/libc/stdio/perror.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/uio.h>
+
+void perror(const char *s)
+{
+	struct iovec iov[4];
+
+	char *errstr = strerror(errno);
+
+	if (s != NULL && *s != '\0') {
+		iov[0].iov_base = (void *)s;
+		iov[0].iov_len = strlen(s);
+		iov[1].iov_base = ": ";
+		iov[1].iov_len = 2;
+	}
+
+	iov[s != NULL && *s != '\0' ? 2 : 0].iov_base = errstr;
+	iov[s != NULL && *s != '\0' ? 2 : 0].iov_len = strlen(errstr);
+	iov[s != NULL && *s != '\0' ? 3 : 1].iov_base = "\n";
+	iov[s != NULL && *s != '\0' ? 3 : 1].iov_len = 1;
+
+	writev(STDERR_FILENO, iov, s != NULL && *s != '\0' ? 4 : 2);
+}