Issue with CTRL+D on Windows Subsystem for Linux

[Guest mdraganic]

Hello,

 

I was working on an assignment using Windows Subsystem for Linux. Below is the C Code that was used to write a mini-shell for this assignment.

 

I ran into an interesting issue using WSL. On line 35, you can see that I call the read function to read in the buffer and it does a check for null. When pressing Control+D, while using WSL, it will go into the if statement and prints the print message on line 36 infinitely and does not stop until I used CTRL+C to exit. When running this program on a Linux machine, it behaves appropriately and prints once, and brings us to the top of the loop.

 

Any ideas as to what this bug could be?

 

Thanks

 

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <sys/wait.h>

#include <errno.h>

#include <string.h>

#include <sys/types.h>

#include <unistd.h>

#include <error.h>

 

char prompt[] = "$ ";

 

static int

Fork()

{

pid_t pid;

 

if ((pid = fork()) < 0)

error(EXIT_FAILURE, errno, "fork error");

return(pid);

}

 

int

main(void)

{

long MAX = sysconf(_SC_LINE_MAX);

char buf[MAX];

pid_t pid;

int status, n;

 

do {

write(STDOUT_FILENO, prompt, strlen(prompt));

fflush(NULL);

memset(buf, 0, MAX);

if((n = read(STDIN_FILENO, buf, MAX)) == 0) {

printf("use exit to exit shell\n");

continue;

}

buf[strlen(buf) - 1] = '\0'; // chomp '\n'

 

if (strncmp(buf, "exit", MAX) == 0) { // match

break;

}

pid = Fork();

if (pid == 0) { // child

execlp(buf, buf, (char *)NULL);

error(EXIT_FAILURE, errno, "exec failure");

}

// parent

if ((pid = waitpid(pid, &status, 0)) < 0)

error(EXIT_FAILURE, errno, "waitpid error");

} while(1);

exit(EXIT_SUCCESS);

}

 

 

 

The program is in C but there are no options available to insert C Code snippets..

 

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