Working on a uni task where I need to use 1 parent process to create 3 child processes and then perform some calculations on each child process. I am stuck on child 2 where I need to load a program which returns the amount of words in a text file and displays it on the console.
This is my word count file:
wc.c
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
int main( int argc, char *argv[]) {
char *wordCountFile = argv[1];
printf("file name passed is %s\n",wordCountFile);
printf("testing\n");
}
the file above does not actually count the words in a file yet as I am just working on getting it to display in the console
In my main program I have
child2 = fork();
wordCountFile = argv[1];
char *cmd = "wc";
char *args[3];
argv[0] = "wc";
argv[1] = wordCountFile;
argv[2] = NULL;
if (child2 == 0){
printf("I am child two my pid is %d \n",getpid());
printf("I will now execute wc program to count all the words in file %s \n",wordCountFile);
execvp(cmd, args);
exit(3);
}
my output is the following:
I am child two my pid is 659
I will now execute wc program to count all the words in file test.txt
I am trying to get the wc program to print to the console
I have compiled wc.c and the program is in the same directory as my main code.
There are some mistakes in your main program. you are modifying argv and passing args to execvpe and you are calling wc program not ./wc. If you are in unix system you probably have /usr/bin/wc, and execvpe will call that program.
Correction to your main program
child2 = fork();
wordCountFile = argv[1];
char *cmd = "./wc";
char *args[3];
args[0] = "./wc";
args[1] = wordCountFile;
args[2] = NULL;
if (child2 == 0){
printf("I am child two my pid is %d \n",getpid());
printf("I will now execute wc program to count all the words in file %s \n",wordCountFile);
execvp(cmd, args);
exit(3);
}
Now main program will call wc program in current directory.