Go4Expert - Help

Hello to all...I 'm new in programming and i want if anybody knows to help me with the following code.It 's about pipes in linux and i want help.So
in following code th function main makes pipe and executes fork. Client then runs in the procedure while server it is executed in the procedure - child.I want if anybody knows to replace the letters A-L so the code can run.

Code:

#include <stdio.h>

#include <unistd.h>

#define MAXBUFF 1024

main()

{

int childpid, pipe1[2], pipe2[2];

if (pipe(pipe1) < 0 || pipe(pipe2) < 0)

printf("can't create pipes\n");

if ((childpid = fork()) < 0)

{ printf("can't fork\n");

}

else if (childpid > 0)

{

/* parent */

close(A);

close(B);

client(C, D);

while (wait((int *) 0) != childpid) /* wait for child */ ;

close(E);

close(F);

exit(0);

} else

{ close(G);

close(H);

server(I, J);

close(K);

close(L);

exit(0);

}

} client(readfd, writefd) int readfd;

int writefd;

{ char buff[MAXBUFF];

int n;

/* Read the filename from standard input, write it to the IPC descriptor */

printf("Write the file name : ");

if (fgets(buff, MAXBUFF, stdin)==NULL)

printf("client: filename read error\n");

n=strlen(buff);

if (buff[n-1]=='\n') n--; /* ignore new line from fgets()

*/ if (write(writefd, buff, n) != n) printf("client: filename write error\n"); /* Read the data from the IPC descriptor and write to standard output */

while ((n=read(readfd, buff, MAXBUFF)) >0)

if (write(1, buff, n) != n)

/* fd 1 stdout */ printf("client: data write error\n");

if (n<0) printf("client: data read error\n");

} server(readfd, writefd) int readfd;

int writefd;

{

char buff[MAXBUFF];

char errmesg[256];

int n, fd;

extern int errno;

/* read the filename from the IPC descriptor */

if ((n=read(readfd, buff, MAXBUFF)) <= 0) printf("server: filename read error\n");

buff[n]='\0'; if ((fd=open(buff, 0)) < 0)

{

/* Error. Format an error message and send it back to the client */ sprintf(errmesg, ": can't open file\n");

strcat(buff, errmesg);

n = strlen(buff);

if (write(writefd, buff, n) != n) printf("server: errmesg write error\n");

}

else

{

/* read the data from the file and write to the IPC descriptor */

while ((n=read(fd, buff, MAXBUFF)) > 0)

if (write(writefd, buff, n) != n) printf("server: data write error\n");

if (n<0)

printf("server: read error\n"); } }

PLEASE HELP!!!!