From c5ad54a55123582b09f9d9d8046623916c2dec4a Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Thu, 14 Jul 2022 17:23:50 +0200
Subject: user/shell/cat: support reading from stdin until eof

---
 src/user/lib/stdlib.c | 17 +++++++++++++++++
 src/user/lib/stdlib.h |  1 +
 2 files changed, 18 insertions(+)

(limited to 'src/user/lib')

diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
index 32b4f06..56b8bb4 100644
--- a/src/user/lib/stdlib.c
+++ b/src/user/lib/stdlib.c
@@ -94,6 +94,23 @@ fail:
 	return NULL;
 }
 
+libc_file *file_clone(const libc_file *f) {
+	handle_t h = _syscall_dup(f->fd, -1, 0);
+	libc_file *f2;
+	if (h < 0) return NULL;
+
+	// TODO file_wrapfd
+	f2 = malloc(sizeof *f2);
+	if (!f2) {
+		close(h);
+		return NULL;
+	}
+	f2->pos = f->pos;
+	f2->eof = f->eof;
+	f2->fd = h;
+	return f2;
+}
+
 int file_read(libc_file *f, char *buf, size_t len) {
 	if (f->fd < 0) return -1;
 
diff --git a/src/user/lib/stdlib.h b/src/user/lib/stdlib.h
index 22227e3..1982e85 100644
--- a/src/user/lib/stdlib.h
+++ b/src/user/lib/stdlib.h
@@ -17,6 +17,7 @@ typedef struct {
 } libc_file;
 libc_file *file_open(const char *path, int flags);
 libc_file *file_reopen(libc_file*, const char *path, int flags);
+libc_file *file_clone(const libc_file*);
 int file_read(libc_file*, char *buf, size_t len);
 int file_write(libc_file*, const char *buf, size_t len);
 void file_close(libc_file*);
-- 
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