Thread: execvp("tail -1f /var/log/apache/www.cs.umu.se/access_log", args) ;

Hello,

This code only gives the "ls" output.
Although running the command "tail -1f /var/log/apache/www.cs.umu.se/access_log"
directly in UNIX it is working, ie it's printing out
the logglines from that webserver...

Please Help!!

Code:

#include <stdio.h>
#include <stropts.h>
#include <poll.h>
#include <unistd.h>


int main(void)
{
	char *args[] = {"tail -1f /var/log/apache/www.cs.umu.se/access_log", NULL};
	execvp("tail -1f /var/log/apache/www.cs.umu.se/access_log", args) ;
	execvp("ls", args) ;

}

KrY

If you have to use "tail" try popen():

Code:

#include <stdio.h>
int main(void)
{
    FILE *fp=popen("tail -1f /var/log/apache/www.cs.umu.se/access_log", "r");
    char tmp[256]={0x0};
  
    while(fgets(tmp, sizeof(tmp), fp)!=NULL
    {
        fprintf(stdout,"%s",  tmp);
    }
    pclose(fp);
    return 0;
}

It would be faster to use fseek to get to the end of the log file, back pedal to the start of the last record, read it, print it. All in C.