#include <sys/resource>int getrusage(int who, struct rusage *r_usage);
利用getrusage可以得到进程的相关资源信息。如：用户开销时间，系统开销时间，接收的信号量等等;
下面是rusage的结构：struct rusage { struct timeval ru_utime; /* user time used */ struct timeval ru_stime; /* system time used */ long ru_maxrss; #define ru_first ru_ixrss long ru_ixrss; /* XXX: 0 */ long ru_idrss; /* XXX: sum of rm_asrss */ long ru_isrss; /* XXX: 0 */ long ru_minflt; /* any page faults not requiring I/O */ long ru_majflt; /* any page faults requiring I/O */ long ru_nswap; /* swaps */ long ru_inblock; /* block input operations */ long ru_oublock; /* block output operations */ long ru_msgsnd; /* messages sent */ long ru_msgrcv; /* messages received */ long ru_nsignals; /* signals received */ long ru_nvcsw; /* voluntary context switches */ long ru_nivcsw; /* involuntary " */ #define ru_last ru_nivcsw };如果参数who是RUSAGE_SELF，则得到的是当前进程的资源信息。如果是RUSAGE_CHILDREN，则将返回当进程的终止掉的子进程和等待子进程的资源信息。当调用成功后，返回0，否则-1；下面是一个例子：
int who = RUSAGE_SELF;struct rusage usage;int ret;
ret = getrusage(who, &usage);
这样你就可以用usage获取你想要的东西了；
