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缘由：
在Linux下C语言的实际编程中，字符串操作是非常常见的，在此整理一下自己常用到的一些例子，方便以后参考。
正文：
参考解答：
1.子串查找&字符查找（strstr/strchr）
void strchr_test() { char *string = "qwerty"; char *e; int index; e = strchr(string, 'e'); if (e == NULL) { printf("Character '%c' not found in '%s'\n", 'e', string); return; } index = (int)(e - string); printf("index of char('%c') in '%s' is %d\n", 'e', string, index); // 2 printf("the rest of str('%s') is '%s'\n", string, e); // 'erty' printf("the rest+1 of str('%s') is '%s'\n", string, e+1); // 'rty' printf("\n");}void strstr_test() { char *str = "sdfadabcGGGGGGGGG"; char *result = strstr(str, "abc"); int position = result - str; printf("substr('%s') of str('%s') index is %d\n", "abc", str, position); // 5 printf("the rest of str('%s') is '%s'\n", str, result); // 'abcGGGGGGGGG' printf("the rest of rest of str('%s') is '%s'\n", str, result+position); // 'GGGGGGG'} |
2.文件按行读取&字符串比较&字符查找&按分隔符切分&字符串转换成整数（getline/strncmp/strchr/strsep/strtol）
#define MAX_PID_COUNT 32int pid_list[MAX_PID_COUNT] = { [ 0 ... MAX_PID_COUNT-1 ] = -1 };int usr1_reload() { FILE *fp; fp = fopen("/tmp/pmon.txt", "r"); /* pid_s = 1, 2, 3, 999 */ if (fp == NULL) { perror("fopen"); return -1; } char *line = NULL, *index = NULL; char pid_str[1024] = {0}, *pid_str_p, *token = NULL, delim[] = ", "; size_t len = 0; ssize_t nread; int i = 0, pid; while ((nread = getline(&line, &len, fp)) != -1) { if (strncmp(line, "pid_s", 5) == 0) { index = strchr(line, '='); if (index) { strncpy(pid_str, index+1, nread-6); pid_str_p = pid_str; token = strsep(&pid_str_p, delim); while(token != NULL){ if (token[0] != '\0') { pid = (int) strtol(token, NULL, 10); if (pid <= 0 || pid == (int)LONG_MIN || pid == (int)LONG_MAX) { } else { if (i < MAX_PID_COUNT) { pid_list[i++] = pid; } } } token = strsep(&pid_str_p, delim); } } break; } } if(line) free(line); fclose(fp); return 0;} |
参考链接：
Linux的C语言中获取子串的索引
https://stackoverflow.com/questions/7500892/get-index-of-substring
Linux的C语言中获取字符的索引
https://stackoverflow.com/questions/3217629/how-do-i-find-the-index-of-a-character-within-a-string-in-c
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