signal.h
signal
sigaction
kill
sigqueue
stdio.h
scanf
printf
sprintf //把格式化数据写入到string中,不安全
snprintf //把格式化数据写入到string中,安全
stdlib.h
malloc
calloc
free
atoi
atol
srand
rand
system
string.h
memcpy
memset
strcat
strncat
strcmp
strcpy
strncpy
strlen
strtok
unistd.h
fork
sleep
read
write
lseek
close
fcntl.h
open //还需要sys/stat.h sys/types.h
pthread.h
mqueue.h
semaphore.h