Advanced Programming in the UNIX® Environment

ptg10805159

912 Solutions to Selected Exercises Appendix C

#include "apue.h"

#include <fcntl.h>

#define DEPTH 1000 /* directory depth */

#define STARTDIR "/tmp"

#define NAME "alonglonglonglonglonglonglonglonglonglongname"

#define MAXSZ (10*8192)

int

main(void)

{

int i;

size_t size;

char *path;

if (chdir(STARTDIR) < 0)

err_sys("chdir error");

for (i = 0; i < DEPTH; i++) {

if (mkdir(NAME, DIR_MODE) < 0)

err_sys("mkdir failed, i = %d", i);

if (chdir(NAME) < 0)

err_sys("chdir failed, i = %d", i);

}

if (creat("afile", FILE_MODE) < 0)

err_sys("creat error");

/*

*The deep directory is created, with a file at the leaf.

*Now let’s try to obtain its pathname.

*/

path = path_alloc(&size);

for ( ; ; ) {

if (getcwd(path, size) != NULL) {

break;

}else {

err_ret("getcwd failed, size = %ld", (long)size);

size += 100;

if (size > MAXSZ)

err_quit("giving up");

if ((path = realloc(path, size)) == NULL)

err_sys("realloc error");

}

}

printf("length = %ld\n%s\n", (long)strlen(path), path);

exit(0);

}

Figure C.3 Create a deep directory tree