template/: +8-pointer-c-strings

8-pointers-c-strings/CMakeLists.txt

@@ -1,5 +1,8 @@
 add_executable(str-literals str-literals.c)
+
 add_executable(strlen strlen.c)
 add_executable(strcpy strcpy.c)
 add_executable(strcmp strcmp.c)
-add_executable(strcat strcat.c)
+add_executable(strcat strcat.c)
+
+add_executable(strcmp-benchmark strcmp-benchmark.c)

8-pointers-c-strings/str-literals.c

@@ -1,9 +1,5 @@
-//
-// Created by hfwei on 2023/11/30.
-// Visualization:
-// https://pythontutor.com/render.html#code=%0A%23include%20%3Cstdio.h%3E%0A%23include%20%3Cstdlib.h%3E%0A%0Aint%20main%28void%29%20%7B%0A%20%20char%20msg%5B%5D%20%3D%20%22Hello%20World!%22%3B%0A%20%20msg%5B0%5D%20%3D%20'N'%3B%0A%20%20printf%28%22%25s%5Cn%22,%20msg%29%3B%0A%0A%20%20char%20*ptr_msg%20%3D%20%22Hello%20World!%22%3B%0A%20%20ptr_msg%5B0%5D%20%3D%20'N'%3B%0A%20%20printf%28%22%25s%5Cn%22,%20msg%29%3B%0A%0A%20%20return%200%3B%0A%7D&cumulative=true&curInstr=6&heapPrimitives=nevernest&mode=display&origin=opt-frontend.js&py=c_gcc9.3.0&rawInputLstJSON=%5B%5D&textReferences=false
+// Created by hfwei on 2024/11/20.
 // See String literals: https://en.cppreference.com/w/c/language/string_literal
-//
 
 #include <stdio.h>
 #include <stdlib.h>

8-pointers-c-strings/strcmp.c

@@ -1,7 +1,4 @@
-//
-// file: strcmp.c
-// Created by hfwei on 2022/11/29.
-//
+// Created by hfwei on 2024/11/20.
 
 #include <stdio.h>
 

8-pointers-c-strings/strcpy.c

@@ -1,6 +1,4 @@
-// file: strcpy.c
-// 7 versions of strcpy
-// Created by hfwei on 2022/11/29.
+// Created by hfwei on 2024/11/20.
 //
 // C Operator Precedence:
 // https://en.cppreference.com/w/c/language/operator_precedence#:~:text=C%20Operator%20Precedence%20%20%20%20Precedence%20,union%20member%20access%20%2028%20more%20rows%20

8-pointers-c-strings/strlen.c

@@ -1,4 +1,3 @@
-// file: strlen.c
 // Created by hfwei on 2024/11/20.
 // See https://en.cppreference.com/w/c/string/byte/strlen
 

template/8-pointers-c-strings/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_executable(str-literals str-literals.c)
+
+add_executable(strlen strlen.c)
+add_executable(strcpy strcpy.c)
+add_executable(strcmp strcmp.c)
+add_executable(strcat strcat.c)

template/8-pointers-c-strings/README.md

@@ -0,0 +1,13 @@
+# `9-more-pointers`
+
+## `strlen.c`
+
+- C string literal
+- `while (str[len++] != '\0')` vs.
+  `while (++str[len] != '\0')` vs.
+  `while (++str[len])`
+- `\0` vs. `0`
+
+## `strcpy.c`
+
+## `strcmp.c`

template/8-pointers-c-strings/str-literals.c

@@ -0,0 +1,20 @@
+// Created by hfwei on 2024/11/20.
+// Visualization:
+// https://pythontutor.com/render.html#code=%23include%20%3Cstdio.h%3E%0A%0Aint%20main%28void%29%20%7B%0A%20%20char%20msg%5B%5D%20%3D%20%22Hello%20World!%22%3B%0A%20%20msg%5B0%5D%20%3D%20'N'%3B%0A%20%20printf%28%22%25s%5Cn%22,%20msg%29%3B%0A%0A%20%20char%20*ptr_msg%20%3D%20%22Goodbye%20World!%22%3B%0A%20%20ptr_msg%5B0%5D%20%3D%20'N'%3B%0A%20%20printf%28%22%25s%5Cn%22,%20msg%29%3B%0A%0A%20%20return%200%3B%0A%7D&cumulative=true&curInstr=0&heapPrimitives=nevernest&mode=display&origin=opt-frontend.js&py=c_gcc9.3.0&rawInputLstJSON=%5B%5D&textReferences=false
+// See String literals: https://en.cppreference.com/w/c/language/string_literal
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(void) {
+  char msg[] = "Hello World!";
+  msg[0] = 'N';
+  printf("%s\n", msg);
+
+  char *ptr_msg = "Goodbye World!";
+  ptr_msg[0] = 'N';
+  printf("%s\n", msg);
+
+  return 0;
+}

template/8-pointers-c-strings/strcat.c

@@ -0,0 +1,27 @@
+// Created by hfwei on 2024/11/20.
+
+#include <stdio.h>
+#include <string.h>
+
+char *StrCat(char *s1, const char *s2);
+char *StrCatGLibC(char *dest, const char *src);
+
+char *StrNCat(char *s1, const char *s2, size_t n);
+size_t StrNLen(const char *s, size_t max);
+char *StrNCatGLic(char *s1, const char *s2, size_t n);
+
+int main(void) {
+  char str[50] = "Hello ";
+  char str2[50] = "World!";
+
+//  strcat(str, str2);
+//  strcat(str, " ...");
+//  strcat(str, " Goodbye World!");
+
+//  strcat(str, str2);
+//  strncat(str, " Goodbye World!", 3);
+
+  puts(str);
+
+  return 0;
+}

template/8-pointers-c-strings/strcmp.c

@@ -0,0 +1,25 @@
+// Created by hfwei on 2024/11/20.
+
+#include <stdio.h>
+
+int StrCmp(const char *s1, const char *s2);
+int StrCmpStd(const char *s1, const char *s2);
+int StrCmpGLibC(const char *p1, const char *p2);
+
+int StrNCmpStd(const char *s1, const char *s2, int n);
+
+int main() {
+  const char *str1 = "hi, C";
+  const char *str2 = "hi, c";
+
+  printf("StrCmp(\"%s\", \"%s\") = %d\n", str1, str2, StrCmp(str1, str2));
+
+  // printf("StrCmpStd(\"%s\", \"%s\") = %d\n",
+  //        str1, str2, StrCmpStd(str1, str2));
+  //
+  // int n = 2;
+  // printf("StrNCmp(\"%s\", \"%s\", %d) = %d\n",
+  //        str1, str2, n, StrNCmp(str1, str2, n));
+
+  return 0;
+}

template/8-pointers-c-strings/strcpy.c

@@ -0,0 +1,27 @@
+// Created by hfwei on 2024/11/20.
+//
+// C Operator Precedence:
+// https://en.cppreference.com/w/c/language/operator_precedence#:~:text=C%20Operator%20Precedence%20%20%20%20Precedence%20,union%20member%20access%20%2028%20more%20rows%20
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void StrCpy1(char *dest, const char *src);
+void StrCpy2(char *dest, const char *src);
+void StrCpy3(char *dest, const char *src);
+void StrCpy4(char *dest, const char *src);
+void StrCpy5(char *dest, const char *src);
+void StrCpy6(char *dest, const char *src);
+
+int main() {
+  const char *src = "Hello World";
+  char *dest = malloc(strlen(src) + 1);
+
+  StrCpy5(dest, src);
+  printf("dest = %s\n", dest);
+
+//  strlen(StrCpyStd(dest, src));
+
+  return 0;
+}

template/8-pointers-c-strings/strlen.c

@@ -0,0 +1,18 @@
+// file: strlen.c
+// Created by hfwei on 2024/11/20.
+// See https://en.cppreference.com/w/c/string/byte/strlen
+
+#include <stdio.h>
+
+int StrLen1(const char *s);
+int StrLen2(const char *s);
+int StrLen3(const char *s);
+
+int main() {
+  char msg[] = "Hello World!";
+
+//  printf("StrLen(%s) = %d\n", msg, StrLen1(msg));
+//  printf("StrLenStd(%s) = %zu\n", msg, StrLenStd(msg));
+
+  return 0;
+}