Hello everyone,
I am stuck with fork(), pid, popen(). I am trying to execute a command, capture it's pid so that when I choose to stop the command I can use kill(). What I have works as far as executing the command and spitting out a pid, but it is the wrong pid. I have tried two versions one with execl and the other with popen and both hail the same results. I am just not understanding fork.
Thanks in advance. Here is the execl example:
Code:#include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/dir.h> #include <signal.h> void print_cwd(); void process(); int main (void) { int c; FILE *IPFile; FILE *OPFile; FILE *IPFILE2; FILE *OPFILE2; IPFile = fopen("Sprint_Evdo","r"); OPFile = fopen("/etc/ppp/peers/Sprint_Evdo","w"); IPFILE2 = fopen("sprint-evdo","r"); OPFILE2 = fopen("/etc/ppp/sprint-evdo","w"); while ((c = fgetc(IPFile)) != EOF) { fputc(c, OPFile); } fclose(IPFile); fclose(OPFile); while ((c = fgetc(IPFILE2)) != EOF) { fputc(c, OPFILE2); } fclose(IPFILE2); fclose(OPFILE2); process(); //printf("%d\n",pid); print_cwd(); return(0); } void print_cwd() { char *cwd = getcwd(NULL, 0); printf("%s\n", cwd); } void process() { int pid; pid = fork(); if ( pid == 0 ) { execl("/usr/sbin/pppd", "pppd", "call", "Sprint_Evdo", (char *)NULL ); } printf("%d\n",pid); }
