/* This program tests the functionality of the pipes. It opens a pipe, forks and executes cat after dup-ing the output end to stdin. Afterwards the parent spews a pile of data into the input end, closes the pipe and waits for cat to exit.*/#include "api.h"#include "lib.h"// the array indicies that pipe() returns.#define READ 0#define WRITE 1// the data to send over the pipe.const char* teststr="This is a drill, this is a drill\n";int main(int argc,char**argv) { int len=strlen(teststr)+1; print("Pipe test 1\n"); int fds[2]; // open a pipe if(sys_pipe(fds)==-1) { printf("Error creating pipes: %d\n",errno); return 1; } printf("Got FDs in:%d\tout=%d\n",fds[READ],fds[WRITE]); if(sys_fork()==0) { // dup it and fork off to cat. sys_close(fds[WRITE]); sys_dup(fds[READ],stdin); int fd=sys_open("bin/cat",0); if(fd==-1) { printf("Couldn't open cat file: %d.\n",errno); return 1; } sys_execve(fd,argv); } else { // close the other end of the pipe sys_close(fds[READ]); for(int i=0;i<5;++i) // spew some data down it. sys_write(fds[WRITE],teststr,len); sys_close(fds[WRITE]); // close it and wait. int c; sys_wait(&c); printf("Cat returned %d.\n",c); } return 0;}