您可以根据http://www.kernel.org/doc/documentation/filesystems/proc.txt检查/
proc // stat文件系统，只需检查task_cpu标志。
没有正确类型和错误检查的示例：
struct pstat{ int pid; //process id char tcomm[256];//filename of the executable char state[2]; //state (R is running, S is sleeping, D is sleeping in an //uninterruptible wait, Z is zombie, T is traced or stopped) int ppid;// process id of the parent process int pgrp;// pgrp of the process int sid;//session id int tty_nr;// tty the process uses int tty_pgrp;// pgrp of the tty int flags;// task flags int min_flt;// number of minor faults int cmin_flt;// number of minor faults with child's int maj_flt;// number of major faults int cmaj_flt;// number of major faults with child's int utime;// user mode jiffies int stime;// kernel mode jiffies int cutime;// user mode jiffies with child's int cstime;// kernel mode jiffies with child's int priority;// priority level int nice;// nice level int num_threads;// number of threads int it_real_value;// (obsolete, always 0) int start_time;// time the process started after system boot int vsize;// virtual memory size int rss;//resident set memory size int rsslim;// current limit in bytes on the rss int start_pre;// address above which program text can run int end_pre;// address below which program text can run int start_stack;// address of the start of the stack int esp;//current value of ESP int eip;//current value of EIP int pending;// bitmap of pending signals int blocked;// bitmap of blocked signals int sigign;// bitmap of ignored signals int sigcatch;// bitmap of catched signals int wchan;// address where process went to sleep int i0;// (place holder) int i1;// (place holder) int exit_signal;// signal to send to parent thread on exit int task_cpu;// which CPU the task is scheduled on int rt_priority;// realtime priority int policy;// scheduling policy (man sched_setscheduler) int blkio_ticks;// time spent waiting for block IO int gtime;// guest time of the task in jiffies int cgtime;// guest time of the task children in jiffies} p ;int main(){ char name[256]; char state[8]; FILE* f = fopen("/proc/self/stat", "r"); fscanf(f, "%d%s%s%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d",&p.pid, &p.tcomm, &p.state, &p.ppid, &p.pgrp, &p.sid, &p.tty_nr, &p.tty_pgrp, &p.flags,&p.min_flt, &p.cmin_flt, &p.maj_flt, &p.cmaj_flt, &p.utime, &p.stime, &p.cutime, &p.cstime,&p.priority, &p.nice, &p.num_threads, &p.it_real_value, &p.start_time, &p.vsize, &p.rss,&p.rsslim, &p.start_pre, &p.end_pre, &p.start_stack, &p.esp, &p.eip, &p.pending, &p.blocked,&p.sigign, &p.sigcatch, &p.wchan, &p.i0, &p.i1, &p.exit_signal, &p.task_cpu, &p.rt_priority, &p.policy,&p.blkio_ticks, &p.gtime, &p.cgtime); printf("CPU %dn", p.task_cpu); return 0; }
