Mine

#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <sys/wait.h>#include <unistd.h>#include <errno.h>#include <string.h>#define MAXLENGTH 255const char *szCommand = "not set";static int pipe1[2];static int pipe2[2];static pid_t pid1;static pid_t pid2;static FILE* pStream1 = (FILE*) 0;static FILE* pStream2 = (FILE*) 0;void BailOut(const char* szMessage);void FreeResources() {	if(pStream1 != (FILE*) 0) {		if(fclose((FILE*) pStream1) == EOF) {			pStream1 = (FILE*) 0;			BailOut("Cannot close pipe");			}		}}void BailOut(const char* szMessage) {	if(szMessage != (const char*) 0) {		fprintf(stderr, "%s", szMessage);		}		FreeResources();	exit(EXIT_FAILURE);}void Usage() {	printf("Just start and write...");}void AllocateResources() {	if(pipe(pipe1) == -1) {		BailOut("Can't create pipe");		}		if(pipe(pipe2) == -1) {		BailOut("Can't create pipe");	}}void FatherProcess() {	char buffer[MAXLENGTH +1];		if(close(pipe1[0]) == -1) {		BailOut("Error closing the read descriptor");		}		if((pStream1 = fdopen(pipe1[1], "w")) == (FILE*) NULL) {		BailOut("Can't open pipe for writing");		}		while(fgets(buffer, MAXLENGTH, stdin) != NULL) {		if(fprintf(pStream1, buffer) < 0)			BailOut("Can't write to pipe");	}		FreeResources();}void ChildProcess() {	char buffer[MAXLENGTH +1];	char reverse[MAXLENGTH +1];	char *p = buffer;				if(close(pipe1[1]) == -1) {		BailOut("Error closing the write descriptor");	}		if((pStream1 = fdopen(pipe1[0], "r")) == (FILE*) 0) {		BailOut("Can't open pipe for reading");	}		if(close(pipe2[0]) == -1) {		BailOut("Error closing the read descriptor");		}		if((pStream2 = fdopen(pipe2[1], "w")) == (FILE*) NULL) {		BailOut("Can't open pipe for writing");		}		while(fgets(buffer, MAXLENGTH, pStream1) != NULL) {		p += strlen(buffer);		p -= 2;				int i;		for(i = 0; i < strlen(buffer); i++, p--) {			reverse[i] = *p;			}		fprintf(pStream2, reverse);	}		FreeResources();}void GrandChildProcess() {	char buffer[MAXLENGTH +1];		if(close(pipe2[1]) == -1) {		BailOut("Error closing the write descriptor");	}		if((pStream2 = fdopen(pipe2[0], "r")) == (FILE*) 0) {		BailOut("Can't open pipe for reading");	}		while(fgets(buffer, MAXLENGTH, pStream2) != NULL) {		printf("%s\n", buffer);		}		}int main(int argc, char** argv) {	pid_t wpid1;	pid_t wpid2;	int status1;	int status2;		szCommand = argv[0];		AllocateResources();		switch(pid1 = fork()) {		case -1:			BailOut("Fork failed");				break;		case 0:			switch(pid2 = fork()) {				case -1:					BailOut("Fork failed");					break;				case 0:					GrandChildProcess();					break;				default:					ChildProcess();					break;			}		default:			FatherProcess();						while((wpid1 = wait(&status1)) != pid1) {				if(wpid1 != -1) {					continue;					}					if(wpid2 != -1) {					continue;					}								if(errno == EINTR) {					continue;				}								BailOut("Error waiting for child process");			}						break;				}		exit(EXIT_SUCCESS);}