commit 4412ab9f43326f812e48b87c9c75529644b39f93
Author: Ondřej Hruška <ondra@ondrovo.com>
Date:   Sat Sep 19 15:48:13 2020 +0200

    a

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..76251f5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,63 @@
+*.swp
+.lock*
+.waf*
+*.pyc
+.project
+.cproject
+.settings
+~*
+pdebug*
+*.tar*
+*.log
+packetlog.db
+*.bin
+*.dat
+*.map
+*~
+*.bak
+
+fsim
+*.img
+
+# ninja files
+build.ninja
+rules.ninja
+.ninja_deps
+.ninja_log
+
+# generated by cmake
+CMakeCache.txt
+*.cmake
+CMakeFiles
+vcom
+Makefile
+*.cbp
+*.a
+
+.idea/
+.DS_Store
+
+build/
+clion-build/
+cmake-build-*/
+
+CMakeLists.txt.user
+
+# Visual Studio clutter
+_ReSharper*
+*.sdf
+*.suo
+*.dir
+*.vcxproj*
+*.sln
+.vs
+CMakeSettings.json
+Win32
+x64
+Debug
+Release
+MinSizeRel
+RelWithDebInfo
+*.opensdf
+
+*.out
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..cf39f1b
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.15)
+project(a)
+
+set(CMAKE_BUILD_TYPE Debug)
+
+add_executable(a main.c strlcat.c)
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..ea06396
--- /dev/null
+++ b/main.c
@@ -0,0 +1,174 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+#include "strlcat.h"
+
+int main () {
+    // Test argument checking
+    assert(0 == strlcpy(NULL, "", 10));
+    assert(0 == strlcpy("", NULL, 10));
+    assert(0 == strlcpy(NULL, NULL, 10));
+    
+    assert(0 == strlncpy(NULL, "", 10, 10));
+    assert(0 == strlncpy("", NULL, 10, 10));
+    assert(0 == strlncpy(NULL, NULL, 10, 10));
+    
+    assert(0 == strlcat(NULL, "", 10));
+    assert(0 == strlcat("", NULL, 10));
+    assert(0 == strlcat(NULL, NULL, 10));
+    
+    assert(0 == strlncat(NULL, "", 10, 10));
+    assert(0 == strlncat("", NULL, 10, 10));
+    assert(0 == strlncat(NULL, NULL, 10, 10));
+
+    
+    // strlcpy
+    {
+        char buf[5] = {0,1,2,3,4};    
+        assert(9 == strlcpy(buf, "abcdefgh", 4));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 'b');
+        assert(buf[2] == 'c');
+        assert(buf[3] == 0);
+        assert(buf[4] == 4);
+    }
+    {
+        char buf[5] = {0,1,2,3,4};    
+        assert(3 == strlcpy(buf, "ab", 5));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 'b');
+        assert(buf[2] == 0);
+        assert(buf[3] == 3);
+    }
+    {
+        char buf[5] = {5,4,3,2,1};    
+        assert(7 == strlcpy(buf, "abcdef", 1));
+        assert(buf[0] == 0); // it puts the zero there
+        assert(buf[1] == 4);
+    }
+    
+    // strlncpy
+    {
+        char buf[5] = {0,1,2,3,4};    
+        assert(3 == strlncpy(buf, "abcdefgh", 4, 2));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 'b');
+        assert(buf[2] == 0);
+        assert(buf[3] == 3);
+    }
+    {
+        char buf[5] = {0,1,2,3,4};    
+        assert(5 == strlncpy(buf, "abcdefgh", 5, 4));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 'b');
+        assert(buf[2] == 'c');
+        assert(buf[3] == 'd');
+        assert(buf[4] == 0);
+    }
+    {
+        char buf[5] = {5,4,3,2,1};    
+        assert(2 == strlncpy(buf, "abcdef", 1, 1));
+        assert(buf[0] == 0); // it puts the zero there
+        assert(buf[1] == 4);
+    }
+    
+    // strlcat
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(2 == strlcat(buf, "a", 8));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 0);
+        assert(buf[2] == 2);
+    }
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(3 == strlcat(buf, "ab", 8));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 'b');
+        assert(buf[2] == 0);
+        assert(buf[3] == 3);
+        
+        assert(5 == strlcat(buf, "xx", 8));
+        assert(0==strcmp(buf,"abxx"));
+        
+        assert(5 == strlcat(buf, "", 8)); // this just sets the terminator
+        assert(0==strcmp(buf,"abxx"));
+        
+        assert(8 == strlcat(buf, "dog", 8));
+        assert(0==strcmp(buf,"abxxdog"));
+        
+        assert(10 == strlcat(buf, "ff", 8));
+        assert(0==strcmp(buf,"abxxdog"));
+    }
+    {
+        char buf[5] = {5,4,3,2,1};
+        assert(7 == strlcat(buf, "abcdef", 1));
+        assert(buf[0] == 0); // it puts the zero there
+        assert(buf[1] == 4);
+    }
+
+
+    // strlncat
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(2 == strlncat(buf, "a", 8, 1));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 0);
+        assert(buf[2] == 2);
+    }
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(2 == strlncat(buf, "a", 8, 50)); // larger n than string size
+        assert(buf[0] == 'a');
+        assert(buf[1] == 0);
+        assert(buf[2] == 2);
+    }
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(26 == strlncat(buf, "abcdefghijklmnopqrstuvwyx", 8, 50)); // larger n than string size & larger than capacity
+        assert(0==strcmp(buf, "abcdefg"));
+    }
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(5 == strlncat(buf, "abcd", 8, 50)); // larger n than string size & larger than capacity
+        assert(0==strcmp(buf, "abcd"));
+        assert(buf[4] == 0);
+        assert(buf[5] == 5);
+    }
+    {
+        char buf[8] = {0,1,2,3,4,5,6,7};
+        assert(3 == strlncat(buf, "abcdef", 8, 2));
+        assert(buf[0] == 'a');
+        assert(buf[1] == 'b');
+        assert(buf[2] == 0);
+        assert(buf[3] == 3);
+
+        assert(5 == strlncat(buf, "xxyyyyy", 8, 2));
+        assert(0==strcmp(buf,"abxx"));
+
+        assert(5 == strlncat(buf, "", 8, 100)); // this just sets the terminator
+        assert(0==strcmp(buf,"abxx"));
+
+        assert(5 == strlncat(buf, "", 8, 0));
+        assert(0==strcmp(buf,"abxx"));
+
+        assert(8 == strlncat(buf, "doggg", 8, 3));
+        assert(0==strcmp(buf,"abxxdog"));
+
+        assert(10 == strlncat(buf, "ffxxx", 8, 2));
+        assert(0==strcmp(buf,"abxxdog"));
+    }
+    {
+        char buf[5] = {5,4,3,2,1};
+        assert(2 == strlncat(buf, "abcdef", 1, 1));
+        assert(buf[0] == 0); // it puts the zero there
+        assert(buf[1] == 4);
+    }
+    
+    // this is a test that asserts are evaluated
+    assert((printf("all ok\n"), 1));
+        
+    return 0;
+}
+
diff --git a/strlcat.c b/strlcat.c
new file mode 100644
index 0000000..9d44fa9
--- /dev/null
+++ b/strlcat.c
@@ -0,0 +1,72 @@
+#include <string.h>
+#include <stddef.h>
+
+size_t strlcat(char *__restrict__ dst, const char *__restrict__ src, size_t capacity)
+{
+    if (!dst) { return 0; }
+    if (!src) { return 0; }
+    size_t used = strnlen(dst, capacity);
+    if (used >= capacity) { used = capacity - 1; }
+    size_t to_print = strlen(src);
+    // to_print does not include the terminator
+    const size_t needed = used + to_print + 1;
+    if (needed > capacity) {
+        to_print = capacity - used - 1;
+    }
+    memcpy(dst + used, src, to_print);
+    *(dst + used + to_print) = '\0';
+    return needed;
+}
+
+size_t strlncat(char *__restrict__ dst, const char *__restrict__ src, size_t capacity, size_t num)
+{
+    if (!dst) { return 0; }
+    if (!src) { return 0; }
+    size_t used = strnlen(dst, capacity);
+    if (used >= capacity) { used = capacity - 1; }
+    size_t to_print = strlen(src);
+    if (to_print > num) {
+        to_print = num;
+    }
+    // to_print does not include the terminator
+    const size_t needed = used + to_print + 1;
+    if (needed > capacity) {
+        to_print = capacity - used - 1;
+    }
+    memcpy(dst + used, src, to_print);
+    *(dst + used + to_print) = '\0';
+    return needed;
+}
+
+size_t strlcpy(char *__restrict__ dst, const char *__restrict__ src, size_t capacity)
+{
+    if (!dst) { return 0; }
+    if (!src) { return 0; }
+    size_t to_print = strlen(src);
+    // to_print does not include the terminator
+    const size_t needed = to_print + 1;
+    if (needed > capacity) {
+        to_print = capacity - 1;
+    }
+    memcpy(dst, src, to_print);
+    *(dst + to_print) = '\0';
+    return needed;
+}
+
+size_t strlncpy(char *__restrict__ dst, const char *__restrict__ src, size_t capacity, size_t num)
+{
+    if (!dst) { return 0; }
+    if (!src) { return 0; }
+    size_t to_print = strlen(src);
+    if (to_print > num) {
+        to_print = num;
+    }
+    // to_print does not include the terminator
+    const size_t needed = to_print + 1;
+    if (needed > capacity) {
+        to_print = capacity - 1;
+    }
+    memcpy(dst, src, to_print);
+    *(dst + to_print) = '\0';
+    return needed;
+}
diff --git a/strlcat.h b/strlcat.h
new file mode 100644
index 0000000..8d843af
--- /dev/null
+++ b/strlcat.h
@@ -0,0 +1,55 @@
+/**
+ * Strcat variant respecting buffer capacity.
+ * Function signatures based on libbsd.
+ * 
+ * Created by Ondřej Hruška on 2020/09/19.
+ */
+
+#ifndef STRLCAT_H
+#define STRLCAT_H
+
+#include <stddef.h>
+
+/**
+ * Append a zero-terminated to a zero-terminated buffer.
+ *
+ * @param[out] dst - destination buffer
+ * @param[in] src - source string
+ * @param[in] capacity - destination buffer capacity
+ * @return The buffer size needed. If > size, then data loss occurred. Returns 0 if invalid arguments were supplied.
+ */
+size_t strlcat(char *__restrict__ dst, const char *__restrict__ src, size_t capacity);
+
+/**
+ * Append at most N characters of a zero-terminated string to a zero-terminated buffer.
+ *
+ * @param[out] dst - destination buffer
+ * @param[in] src - source string
+ * @param[in] capacity - destination buffer capacity
+ * @param[in] num - number of bytes to write
+ * @return The buffer size needed. If > size, then data loss occurred. Returns 0 if invalid arguments were supplied.
+ */
+size_t strlncat(char *__restrict__ dst, const char *__restrict__ src, size_t capacity, size_t num);
+
+/**
+ * Copy a zero-terminated string to a zero-terminated buffer.
+ * 
+ * @param[out] dst - destination buffer
+ * @param[in] src - source string
+ * @param[in] capacity - destination buffer capacity
+ * @return The buffer size needed. If > size, then data loss occurred. Returns 0 if invalid arguments were supplied.
+ */
+size_t strlcpy(char *__restrict__ dst, const char *__restrict__ src, size_t capacity);
+
+/**
+ * Copy at most N characters of a zero-terminated string to a zero-terminated buffer.
+ * 
+ * @param[out] dst - destination buffer
+ * @param[in] src - source string
+ * @param[in] capacity - destination buffer capacity
+ * @param[in] num - number of bytes to write
+ * @return The buffer size needed. If > size, then data loss occurred. Returns 0 if invalid arguments were supplied.
+ */
+size_t strlncpy(char *__restrict__ dst, const char *__restrict__ src, size_t capacity, size_t num);
+ 
+#endif //STRLCAT_H