I have a program in C. Let's assume its compiled name is a.out (default).
When I use the following command to execute it ...
./a.out < arquivo.txt
... how do I read the content of arquivo.txt within the program (in function main same)?
Basically what you need to do is read the stdin which is where the file data will come from. A simplified implementation would be this:
#include <stdlib.h>
#include <stdio.h>
#define BUFF_SIZE 1024
int main(void) {
char buffer[BUFF_SIZE];
while (fgets(buffer, BUFF_SIZE, stdin) != NULL) {
printf("%s", buffer);
}
return 0;
}
In this way whatever comes through the pipe of the operating system will be printed on the screen. The pipe will fetch a data source, it may be a file but may be another source as well.