ftruncate

platform/src/linux/mod.rs

@@ -63,6 +63,12 @@ pub fn fsync(fildes: c_int) -> c_int {
     }
 }
 
+pub fn ftruncate(fildes: c_int, length: off_t) -> c_int {
+    unsafe {
+        syscall!(FTRUNCATE, fildes, length) as c_int
+    }
+}
+
 #[cfg(target_arch = "x86_64")]
 pub fn open(path: *const c_char, oflag: c_int, mode: mode_t) -> c_int {
     unsafe {

platform/src/redox/mod.rs

@@ -51,6 +51,10 @@ pub fn fsync(fd: c_int) -> c_int {
     syscall::fsync(fd as usize)? as c_int
 }
 
+pub fn ftruncate(fd: c_int, len: off_t) -> {
+    syscall::ftruncate(fd as usize, len as usize)? as c_int
+}
+
 pub fn open(path: *const c_char, oflag: c_int, mode: mode_t) -> c_int {
     let path = unsafe { c_str(path) };
     syscall::open(path, (oflag as usize) | (mode as usize)).unwrap() as c_int

src/unistd/src/lib.rs

@@ -161,7 +161,7 @@ pub extern "C" fn fsync(fildes: c_int) -> c_int {
 
 #[no_mangle]
 pub extern "C" fn ftruncate(fildes: c_int, length: off_t) -> c_int {
-    unimplemented!();
+    platform::ftruncate(fildes, length)
 }
 
 #[no_mangle]