字符测试篇 isalnum isalpha isascii iscntrl isdigit isgraphis islower isprint isspace ispunct isupper isxdigit 字符串转换篇 atof atoi atol gcvt strtod strtol strtoul toascii tolower toupper 内存控制篇 calloc free getpagesize malloc mmap munmap 日期时间篇 asctime ctime gettimeofday gmtime localtime mktime settimeofday time 内存及字符串操作篇 bcmp bcopy bzero index memccpy memchr memcmp memcpy memmove memset rindex strcasecmp strcat strchr strcmp strcoll strcpy strcspn strdup strlen strncasecmp strncat strncpy strpbrk strrchr strspn strstr strtok 常用数学函数篇 abs acos asin atan atan2 ceil cos cosh exp frexp ldexp log log10 pow sin sinh sqrt tan tanh 用户组篇 endgrent endpwent endutent fgetgrent fgetpwent getegid geteuid getgid getgrent getgrgid getgrnam getgroups getpw getpwent getpwnam getpwuid getuid getutent getutid getutline initgroups pututline seteuid setfsgid setfsuid setgid setgrent setgroups setpwent setregid setreuid setuid setutent utmpname 数据结构及算法篇 crypt bsearch lfind lsearch qsort rand srand 文件操作篇 close creat dup dup2 fcntl flock fsync lseek mkstemp open read sync write 文件内容操作篇 clearerr fclose fdopen feof fflush fgetc fgets fileno fopen fputc fputs fread freopen fseek ftell fwrite getc getchar gets mktemp putc putchar rewind setbuf setbuffer setlinebuf setvbuf ungetc 进程操作篇 atexit execl execlp execv execve execvp exit _exit vfork getpgid getpgrp getpid getppid getpriority nice on_exit setpgid setpgrp setpriority system wait waitpid fprintf fscanf printf sacnf sprintf sscanf vfprintf vfscanf vprintf vscanf vsprintf vsscanf 文件权限控制篇 access alphasort chdir chmod chown chroot closedir fchdir fchmod fchown fstat ftruncate getcwd link lstat opendir readdir readlink remove rename rewinddir seekdir stat symlink telldir truncate umask unlink utime utimes 信号处理篇 alarm kill pause sigaction sigaddset sigdelset sigemptyset sigfillset sigismember signal sigpending sigprocmask sleep ferror perror strerror mkfifo pclose pipe popen 接口处理篇 accept bind connect endprotoent endservent getsockopt htonl htons inet_addr inet_aton inet_ntoa listen ntohl ntohs recv recvfrom recvmsg send sendmsg sendto setprotoent setservent setsockopt shutdown socket 环境变量篇 getenv putenv setenv 终端控制篇 getopt isatty select ttyname