void invert(char* s) {
int i;
char temp;
int sl = strlen(s);
for (i=0; i<sl/2; i++) {
temp = s[i];
s[i] = s[sl-i-1];
s[sl-i-1] = temp;
}
swapCase(s);
}
void encoder(char* argv){
int fd1[2];
int fd2[2];
int nbytes;
int counter;
char readbuffer[256];
char* string;
if(argv == NULL){
string = getString();
}
else{
string = argv;
}
pid_t childpid;
pipe(fd1);
pipe(fd2);
if((childpid = fork()) == -1){
perror("fork");
exit(1);
}
//child process
if(childpid == 0){
close(fd1[STDOUT]); //close extra child output pipe
close(fd2[STDIN]); //close extra child input pipe
write(fd2[STDOUT], string, (strlen(string)+1)); //send message to parent process
read(fd1[STDIN], readbuffer, sizeof(readbuffer)); //receive encoded message from parent
printf("Encoded message: \t%s\n", readbuffer);
exit(0);
}
//parent process
else{
close(fd2[STDOUT]); //close parent output pipe
close(fd1[STDIN]); //close parent input pipe
nbytes = read(fd2[STDIN], readbuffer, sizeof(readbuffer)); //read original message from child
printf("Original message: \t%s", readbuffer);
//encode message
for(counter = 0; counter < nbytes - 1; counter++){
readbuffer[counter] = swapCase(encode(readbuffer[counter]));
}
write(fd1[STDOUT], readbuffer, (strlen(readbuffer)+1)); //send message back to child
}
}