Question

变量可以包含3-4HYTER3（OK）或[ID] =＆＃34; 3-4HYTER3＆＃34; （错误的）

需要在字符串中剪切错误符号，如：[ID] =＆＃34; 3-4HYTER3＆＃34; 应该是：3-4HYTER3

如何找到错误的字符串[ID] = 3-4HYTER3并剪切[ID] =＆＃34; ＆＃34; ？

拜托，帮助我！

Answer 1

如果我了解你，你需要像 -

这样的东西

const char *removeId(const char *input) {
  const char *pattern = "[ID] = \"";
  const size_t patternLen = strlen(pattern);
  if (strncmp(input, pattern, patternLen) == 0) {
    size_t outLen = strlen(input) - patternLen;
    char *out = (char *) malloc(sizeof(char *) * outLen);
    strncpy(out, input+patternLen, outLen - 1);
    out[outLen - 1] = '\0';
    return out;
  }
  return input;
}

int main(int argc, char *argv[]) {
  const char *input = "[ID] = \"3-4HYTER3\"";
  puts(input);
  puts(removeId(input));
}

输出

[ID] = "3-4HYTER3"
3-4HYTER3

Answer 2

除了关于删除不需要的ID的答案之外，如果要搜索大量字符串以识别包含不需要的字符的字符串，例如示例中的=符号，则可以使用简单的函数来搜索字符串中的字符并根据需要采取措施：

/* char in string - returns 1 if found, 0 otherwise
   (could make (void *) and return 'p' or NULL)
*/
int
chr_in_str (char *str, char c)
{
    char *p = str;
    while (*p != '\0') {
        if (*p == c)
            return 1;
        p++;
    }
    return 0;
}

只需在测试中传递字符串和感兴趣的字符：

if (chr_in_str (str, '='))
    removeId (str);      // removeId from Elliots answer

Answer 3

#include <stdio.h>
#include <stdbool.h>
#include <string.h>

#define VALID_CHAR_SET "abcdefghijklmnopqrstuvwxyz"\
                       "ABCDEFGHIJKLMNOPQRSTUVWXYZ"\
                       "0123456789"\
                       "-_"

static inline bool isValidChar(char ch){
    //or use is isalnum() etc.. in <ctype.h>
    // return isalnum(ch) || ch == '-' /* ... */;
    return !!strchr(VALID_CHAR_SET, ch);//Simple implementation
}

int removeInvalidChar(char *str){
    char *to;
    int count = 0;
    for(to=str;*str;++str){
        if(isValidChar(*str))
            *to++ = *str;
        else
            ++count;
    }
    *to = '\0';
    return count;
}

int main(){
    char str[]="\"3-4HYTER3\"";
    if(removeInvalidChar(str)){
        printf("removed the invalid character.\n");
    }
    printf("%s\n", str);

    return 0;
}

在C中查找字符串并从左侧和右侧剪切一些符号

3 个答案: