longpath.c

UNIX高级环境编程（第二版）文件系统部分的程序

#include    <sys/types.h>
#include    <sys/stat.h>
#include    <fcntl.h>
#include    "ourhdr.h"

#define    DEPTH    100            /* directory depth */
#define    MYHOME    "/home/stevens"
#define    NAME    "alonglonglonglonglonglonglonglonglonglongname"

int
main(void)
{
    int        i, size;
    char    *path;

    if (chdir(MYHOME) < 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 and obtain its pathname.
     */

    path = path_alloc(&size);
    for ( ; ; ) {
        if (getcwd(path, size) != NULL)
            break;
        else {
            err_ret("getcwd failed, size = %d", size);
            size += 100;
            if ( (path = realloc(path, size)) == NULL)
                err_sys("realloc error");
        }
    }
    printf("length = %d\n%s\n", strlen(path), path);

    exit(0);
}