字符串操作

2.1 strtok()

2.2 strstr()

2.3 strspn()

2.4 strrchr()

2.5 strpbrk()

2.6 strncpy()

2.7 strncat()

2.8 strncasecmp()

2.9 strlen()

2.10 strdup()

2.11 strchr()

2.12 strcspn()

2.13 strcpy()

2.14 strcoll()

2.15 strcmp()

2.16 strcat()

2.17 strcasecmp()

2.18 rindex()

2.19 index()

2.20 toupper()

2.21 tolower()

2.22 toascii()

2.23 strtoul()

2.24 strtol()

2.25 strtod()

2.26 gcvt()

2.27 atol()

2.28 atoi()

2.29 atof()