嵌入式 一个进程获取另一个指定名称进程的PID

1、我们可以直接使用管道获取

ps u | awk '/\.\/sigrecevice$/{print $2}'

注意：转义字符打印的时候需要两次转义：打印“\t” 为“\\t”

2、如果想获取之后保存在变量中，则实现代码如下：

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#define __DEBUG__
#ifdef __DEBUG__
#define msg_print(...) printf(__VA_ARGS__)
#else
#define msg_print(...)
#endif
#define MAX_VALUE_LEN 32
int joseph_get_name_pid(const char *key, char *value);
int joseph_get_name_pid(const char *key, char *value)
{
    FILE *stream = NULL;
    char cmd[64] = {0};
    char  buf[8] = {0};
    if(NULL == key || 0 == strlen(key)){
 msg_print("invalid parameter!\n");
 return -1;
    }
    strcpy(buf,"\\.\\/");
    printf("%s %d The buf is %s\n",__FUNCTION__,__LINE__,buf);
    //sprintf(cmd, "ps u | awk '/%s$/{print $2}' | sed -n '1p'",key);
    sprintf(cmd, "ps u | awk '/%s%s$/{print $2}'",buf,key);
    msg_print("cmd = %s\n",cmd);
    stream = popen(cmd,"r");
    if(fread(value, sizeof(char), MAX_VALUE_LEN, stream) <= 0){
 pclose(stream);
 return -1;
    }
    strcpy(value + strlen(value) - 1, "\0");
    msg_print("%s = %s\n", key, value);
    pclose(stream);
    return 0;
}
int main(int argc,char *argv[])
{
    char value[32] = {0};
    int name_pid = 0;
    if(argc != 2)
    {
 printf("%s %d The param is two !\n",__FUNCTION__,__LINE__);
 return -1;
    }
    joseph_get_name_pid(argv[1] ,value);
    if(strlen(value) == 0)
    {
 printf("%s %d The %s is not running !\n",__FUNCTION__,__LINE__,argv[1]);
 return -1;
    }
    name_pid = atoi(value);
    printf("%s %d The pid is %s(char) ,the pid length is %d !\n",__FUNCTION__,__LINE__,value,strlen(value));
    printf("%s %d The pid is %d(int) !\n",__FUNCTION__,__LINE__,name_pid);
    return 0;
}