Linux Nic status detection using C language + shell

No explanation. The Code directly requires the linux environment to have grep and awk (optional for awk)

#include 
 
  #include 
  
   #include 
   
    #include 
    
     int get_if_status(char *if_name){    char    buffer[BUFSIZ];char    cmd[100];    FILE    *read_fp;    int        chars_read;    int        ret =0;       memset( buffer, 0, BUFSIZ );    memset( cmd, 0, 100 );sprintf(cmd, "ifconfig -a | grep %s",if_name);    read_fp = popen(cmd, "r");    if ( read_fp != NULL )    {        chars_read = fread(buffer, sizeof(char), BUFSIZ-1, read_fp);pclose(read_fp);        if (chars_read > 0)        {            ret = 1;        }        else        {fprintf(stderr, "%s: NO FOUND\r\n",if_name);return 0;        }    }if(ret == 1){memset( buffer, 0, BUFSIZ );memset( cmd, 0, 100 );sprintf(cmd, "ifconfig |grep %s",if_name);read_fp = popen(cmd, "r");if ( read_fp != NULL ){    chars_read = fread(buffer, sizeof(char), BUFSIZ-1, read_fp);    pclose(read_fp);    if (chars_read > 0)    {        ret = 2;    }    else    {fprintf(stderr, "%s: DOWN\r\n",if_name);return 1;    }}}if(ret == 2){memset( buffer, 0, BUFSIZ );memset( cmd, 0, 100 );sprintf(cmd, "ifconfig %s | grep RUNNING |  awk '{print $3}'",if_name);read_fp = popen(cmd, "r");if ( read_fp != NULL ){    chars_read = fread(buffer, sizeof(char), BUFSIZ-1, read_fp);    pclose(read_fp);    if (chars_read > 0)    {fprintf(stderr, "%s: LINKED\r\n",if_name);return 3;    }    else    {fprintf(stderr, "%s: UNPLUGGED\r\n",if_name);return 2;    }}}return -1;}int main(int argc, char* argv[]){    int i=0;if(argc != 2){fprintf(stderr, "usage: %s 
     
      ", argv[0]);return -1;}    i = get_if_status(argv[1]);    printf( "if_status = %d\n", i );    return 0;}
     
    
   
  
 

Embedded compilation of mips-linux-gnu-gcc-mips32-EL-mhard-float-Wall-o netlink. c

Test Results

# ./netlink eth100eth100: NO FOUNDif_status = 0# # ifconfig eth0 down# ./netlink eth0  eth0: DOWNif_status = 1# # ifconfig eth0 up# ./netlink eth0eth0: UNPLUGGEDif_status = 2## ./netlink eth0eth0: LINKEDif_status = 3