Implement `mkstemp` and `mkostemps` (squashed)

Cargo.lock

@@ -443,6 +443,7 @@ dependencies = [
  "cbindgen 0.5.2",
  "ctype 0.1.0",
  "errno 0.1.0",
+ "fcntl 0.1.0",
  "platform 0.1.0",
  "rand 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "string 0.1.0",

src/stdlib/Cargo.toml

@@ -16,3 +16,4 @@ string = { path = "../string" }
 time = { path = "../time" }
 unistd = { path = "../unistd" }
 wchar = { path = "../wchar" }
+fcntl = { path = "../fcntl" }

src/stdlib/src/lib.rs

@@ -5,6 +5,7 @@
 
 extern crate ctype;
 extern crate errno;
+extern crate fcntl;
 extern crate platform;
 extern crate rand;
 extern crate string;
@@ -12,7 +13,7 @@ extern crate time;
 extern crate unistd;
 extern crate wchar;
 
-use core::{ptr, str};
+use core::{ptr, slice, str};
 use rand::distributions::Alphanumeric;
 use rand::prng::XorShiftRng;
 use rand::rngs::JitterRng;
@@ -21,6 +22,7 @@ use string::*;
 use wchar::*;
 
 use errno::*;
+use fcntl::*;
 use platform::types::*;
 
 mod sort;
@@ -456,9 +458,57 @@ fn get_nstime() -> u64 {
     ts.tv_nsec as u64
 }
 
-// #[no_mangle]
+#[no_mangle]
+pub extern "C" fn mkostemps(name: *mut c_char, suffix_len: c_int, mut flags: c_int) -> c_int {
+    use core::iter;
+    let len = unsafe { strlen(name) } as c_int;
+
+    if len < 6 || suffix_len > len - 6 {
+        unsafe { platform::errno = errno::EINVAL };
+        return -1;
+    }
+
+    for i in (len - suffix_len - 6)..(len - suffix_len) {
+        if unsafe { *name.offset(i as isize) } != b'X' as c_char {
+            unsafe { platform::errno = errno::EINVAL };
+            return -1;
+        }
+    }
+
+    flags -= flags & O_ACCMODE;
+
+    let mut rng = JitterRng::new_with_timer(get_nstime);
+    rng.test_timer();
+
+    for _retries in 0..100 {
+        let char_iter = iter::repeat(()).map(|()| rng.sample(Alphanumeric)).take(6).enumerate();
+        unsafe {
+            for (i, c) in char_iter {
+                *name.offset((len as isize) - (suffix_len as isize) - (i as isize) - 1) = c as c_char
+            }
+        }
+
+        let fd = platform::open(name, flags | O_RDWR | O_CREAT | O_EXCL, 0600);
+
+        if fd >= 0 {
+            return fd;
+        }
+
+        unsafe { platform::errno = errno::EEXIST };
+    }
+
+    unsafe {
+        for i in 0..6 {
+            *name.offset((len as isize) - (suffix_len as isize) - (i as isize) - 1) = b'X' as c_char;
+        }
+    }
+
+    -1
+}
+
+#[no_mangle]
 pub extern "C" fn mkstemp(name: *mut c_char) -> c_int {
-    unimplemented!();
+    mkostemps(name, 0, 0)
 }
 
 // #[no_mangle]

tests/.gitignore

@@ -30,6 +30,7 @@ localtime
 math
 mem
 mktime
+mkostemps
 pipe
 printf
 rename

tests/Makefile

@@ -22,6 +22,7 @@ EXPECT_BINS=\
 	math \
 	mem \
 	mktime \
+	mkostemps \
 	pipe \
 	printf \
 	rename \

tests/mkostemps.c

@@ -0,0 +1,27 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char** argv) {
+    char* file_name = (char*) calloc(18, sizeof(char));
+    strcpy(file_name, "tempXXXXXX.suffix");
+    int fd = mkostemps(file_name, 7, 0);
+    FILE* fp = fdopen(fd, "w+");
+    printf("Start unchanged: %d\n", strncmp(file_name, "temp", 4));
+    printf("End unchanged: %d\n", strcmp(file_name + 4 + 6, ".suffix"));
+
+    char* write = "Writing to file";
+    fputs(write, fp);
+
+    char buffer[sizeof write];
+    memset(buffer, 0, sizeof buffer);
+    fgets(buffer, strlen(buffer), fp);
+    if (strcmp(write, buffer)) {
+        printf("Read & Write Successful\n");
+    } else {
+        printf("Read & Write Failed\n");
+    }
+    fclose(fp);
+    remove(file_name);
+    return 0;
+}