From 826cf0c61c2e0712914f986e756d1fdef56f9c5c Mon Sep 17 00:00:00 2001
From: Justin Raymond <justin.raymond.14@gmail.com>
Date: Sat, 10 Mar 2018 11:10:19 -0500
Subject: [PATCH] implement strrchr
---
src/string/src/lib.rs | 13 +++++++++++--
tests/Makefile | 1 +
tests/string/strrchr.c | 22 ++++++++++++++++++++++
3 files changed, 34 insertions(+), 2 deletions(-)
create mode 100644 tests/string/strrchr.c
diff --git a/src/string/src/lib.rs b/src/string/src/lib.rs
index a3d454fe..bbb1a53c 100644
--- a/src/string/src/lib.rs
+++ b/src/string/src/lib.rs
@@ -223,8 +223,17 @@ pub extern "C" fn strpbrk(s1: *const c_char, s2: *const c_char) -> *mut c_char {
}
#[no_mangle]
-pub extern "C" fn strrchr(s: *const c_char, c: c_int) -> *mut c_char {
- unimplemented!();
+pub unsafe extern "C" fn strrchr(s: *const c_char, c: c_int) -> *mut c_char {
+ let len = strlen(s) as isize;
+ let c = c as i8;
+ let mut i = len - 1;
+ while *s.offset(i) != 0 && i >= 0 {
+ if *s.offset(i) == c {
+ return s.offset(i) as *mut c_char;
+ }
+ i -= 1;
+ }
+ ptr::null_mut()
}
#[no_mangle]
diff --git a/tests/Makefile b/tests/Makefile
index 0726ba10..8ca12a9a 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -25,6 +25,7 @@ BINS=\
sprintf \
stdlib/strtol \
string/strncmp \
+ string/strrchr \
unlink \
write
diff --git a/tests/string/strrchr.c b/tests/string/strrchr.c
new file mode 100644
index 00000000..7edc9804
--- /dev/null
+++ b/tests/string/strrchr.c
@@ -0,0 +1,22 @@
+#include <string.h>
+#include <stdio.h>
+
+
+int main(int argc, char* argv[]) {
+ char s0[] = "hello, world";
+ char* ptr = strrchr(s0, 'l');
+ if (ptr != &s0[10]) {
+ printf("%p != %p\n", ptr, &s0[10]);
+ printf("strrchr FAIL , exit with status code %d\n", 1);
+ return 1;
+ }
+ char s1[] = "";
+ ptr = strrchr(s1, 'a');
+ if (ptr != NULL) {
+ printf("%p != 0\n", ptr);
+ printf("strrchr FAIL, exit with status code %d\n", 1);
+ return 1;
+ }
+ printf("strrch PASS, exiting with status code %d\n", 0);
+ return 0;
+}
--
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