Vuser中常用的C语言函数

strchr函数与strrchr函数查找指定字符（仅能判断字符，不能是字符串）在字符串中的位置

Action()
{
//    strchr函数用于查找指定字符在一个字符串中第1次出现的位置，然后返回指向该位置的指针；
//    strrchr函数用户查找指定字符在一个字符串中最后1次出现的位置，然后返回指向该位置的指针。
//    语法结构
//        char *strchr(const char *string,int c);
//        char *strrchr(const char *string,int c);
    
    
    char *string = "I'm a young soul in this very strange world";
    char *first_a, *last_a;
    
    first_a = (char *)strchr(string, 'a');
    lr_output_message("The first occurrence of a: %s", first_a);
    
    last_a = (char *)strrchr(string, 'a');
    lr_output_message("The last occurrence of a: %s", last_a);
    
    return 0;
}
-----------------------------------------------------------------------------------
Running Vuser...
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(14): The first occurrence of a: a young soul in this very strange world
Action.c(17): The last occurrence of a: ange world
Ending action Action.
Ending iteration 1.
Ending Vuser...

strcpy函数与strncpy函数复制字符串

Action()
{
//    strcpy函数是把一个字符串复制到另一个字符串中；
//    strncpy函数是把一个字符串中的指定长度复制到另一个字符串中，如果指定长度超过了字符串长度，则会复制整个字符串。
//    语法结构
//        strcpy:    char *strcpy(char *dest, const char *source);
//        strncpy:    char *strncpy(char *dest,const char *source, size_t n);
//    参数dest是目标字符串，source是源字符串，n是要复制的长度。
        
    
    char test[50];
    char ntest[50];
    strcpy(test, "Copies one string to another.");
    lr_output_message("%s", test);
    
    strncpy(ntest, "Copies the first n characters of one string to another?", 30);
    lr_output_message("%s", ntest);
        
    return 0;
}

----------------------------------------------------------------------------------
Running Vuser...
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(14): Copies one string to another.
Action.c(17): Copies the first n characters 
Ending action Action.
Ending iteration 1.
Ending Vuser...

strcmp函数与stricmp函数用于按照字母表顺序来比较两个字符串的大小

Action()
{
//    strcmp函数与stricmp函数用于按照字母表顺序来比较两个字符串的大小，前者比较时区分字符串的大小写，后者比较时不区分字符串的大小写
//    语法结构
//        strcmp:    int strcmp(const char *string1, const char *string2);
//        stricmp:    int stricmp(const char *string1, const char *string2);
        
    int result;
    char tmp[20];
    char string1[] = "He is a test";
    char string2[] = "He is a TEST";
    
//    strcmp区分大小写
    result = strcmp(string1, string2);
    if(result > 0)strcpy(tmp, "greater than");
    else if(result < 0)strcpy(tmp, "less than");
    else strcpy(tmp, "equal to");
    
    lr_output_message("strcmp: String1 is %s string2", tmp);
    
//    stricmp不区分大小写
    result = stricmp(string1, string2);
    if(result > 0)strcpy(tmp, "greater than");
    else if(result < 0)strcpy(tmp, "less than");
    else strcpy(tmp, "equal to");
    
    lr_output_message("stricmp: String1 is %s string2", tmp);
    
    return 0;
}

---------------------------------------------------------------------------------------
Running Vuser...
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(19): strcmp: String1 is greater than string2
Action.c(27): stricmp: String1 is equal to string2
Ending action Action.
Ending iteration 1.
Ending Vuser...

strcat函数与strncat函数都是字符串连接函数

Action()
{
//    strcat函数与strncat函数都是字符串连接函数；
//    strcat：把一个字符串全部内容复制到另一个字符串后面；
//    strncat：把一个字符串的指定长度复制到另一个字符串的后面，如果指定长度超过了字符串的长度，则会复制整个字符串。
//    语法结构：
//        strcat:    char *strcat(char *to_string,const char *from_string);
//        strncat:    char *strncat(char *to_string,const char *from_string, size_t n);
    
    char str1[] = "This is ";
    char str2[] = "a ";
    char str3[] = "strcat&strncat ";
    char str4[] = "test!";
    lr_output_message("The str1 is: %s", str1);
    
    strcat(str1, str2);
    lr_output_message("The str1 is: %s", str1);
    
    strncat(str1, str3, 100);
    lr_output_message("The str1 is: %s", str1);
    
    strcat(str1, str4, 5);
    lr_output_message("The str1 is: %s", str1);
    
    return 0;
}

-------------------------------------------------------------------------
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(14): The str1 is: This is 
Action.c(17): The str1 is: This is a 
Action.c(20): The str1 is: This is a strcat&strncat 
Action.c(23): The str1 is: This is a strcat&strncat test!
Ending action Action.

sprintf函数：把一个字符串格式化后输入到另一个字符串中，然后返回写入的字符数量

Action()
{
//    sprintf函数：把一个字符串格式化后输入到另一个字符串中，然后返回写入的字符数量
//    语法结构：
//        sprintf:    int sprintf(char *string,const char *format_string[,args]);
    
    char test[30];
    int a=2,b=8;
    sprintf(test, "Add Test: a=%d,b%d,a+b=%d.", a, b, a+b);    // 字符串中的“”是字符串结束符。
    lr_output_message(test);
    
    return 0;
}

-------------------------------------------------------------------------
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(10): Add Test: a=2,b8,a+b=10.
Ending action Action.
Ending iteration 1.

strlwr函数：把一个字符串全部变小写；
strupr函数：把一个字符串全部变大写；

Action()
{
//    strlwr函数：把一个字符串全部变小写；
//    strupr函数：把一个字符串全部变大写；
//    语法结构：
//        strlwr:    char *strlwr(char *string);
//        strupr:    char *strupr(char *string);
    
    char str[] = "ThIS is A tEst.";
    char *lowerstr, *upperstr;
    
    lowerstr = (char *)strlwr(str);
    lr_output_message("lowerstr=%s", lowerstr);
    lr_output_message("str=%s", str);
    
    upperstr = (char *)strupr(str);
    lr_output_message("upperstr=%s", upperstr);
    lr_output_message("str=%s", str);
        
    return 0;
}

-------------------------------------------------------------------------
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(13): lowerstr=this is a test.
Action.c(14): str=this is a test.
Action.c(17): upperstr=THIS IS A TEST.
Action.c(18): str=THIS IS A TEST.
Ending action Action.
Ending iteration 1.

atoi函数：把一个字符串转为整数；

itoa函数：把整数转为字符串；

Action()
{
//    atoi函数：把一个字符串转为整数；
//    itoa函数：把整数转为字符串；
//    语法结构：
//        atoi:    int atoi(const char *string);
//        itoa:    int itoa(int value,char *string,int radix);
//            参数value是要转换的整数，string是用例保存转换结果的字符串，radix是转换时的进制。
    
    int j, i;
    char *s = "aaa 111 bbb 222";
    char str_int[10], str_hex[10];
    
    j = atoi(s);
    lr_output_message("Result:%d", j);
    
    s = "111 bbb 222";
    j = atoi(s);
    lr_output_message("Result:%d", j);


    i=56;
    itoa(i, str_int, 10);
    lr_output_message("New file name %s", str_int);
    
    itoa(i, str_hex, 16);
    lr_output_message("New file name %s", str_int);
    
    return 0;
}

-------------------------------------------------------------------------
Starting iteration 1.
Maximum number of concurrent connections per server: 6      [MsgId: MMSG-26989]
Starting action Action.
Action.c(15): Result:0
Action.c(19): Result:111
Action.c(24): New file name 56
Action.c(27): New file name 56
Ending action Action.
Ending iteration 1.