UNIX 高级环境编程 第四章作业

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <sys/resource.h>
#include <signal.h>

#ifndef MAX_NAME
#define MAX_NAME 1024
#endif

#define YH_FILE             1
#define YH_ISDIR            2
#define YH_STAT_FAIL        3
#define YH_OPEN_DIR_FAIL    4
#define YH_MEMORY_FAIL      5
#define YH_CLOSE_DIR_FAIL   6

static size_t max_path_len;
static char *max_path_buf;
static size_t ndir,  // directory
              nchr,  // special character
              nsock, // socket
              nreg,  // regular
              nlnk,  // symbolic link
              nfifo, // fifo
              nblk;  // special block

static int __handle_one_file(const char *pathname, struct stat *st, int flag) {
    switch (flag) {
        case YH_FILE:
            if (S_ISREG(st->st_mode))       nreg++;
            else if (S_ISCHR(st->st_mode))  nchr++;
            else if (S_ISBLK(st->st_mode))  nblk++;
            else if (S_ISLNK(st->st_mode))  nlnk++;
            else if (S_ISSOCK(st->st_mode)) nsock++;
            else if (S_ISFIFO(st->st_mode)) nfifo++;
            else {
                printf("%s unkonw fail\n", pathname);
                return -1;
            }
            break;
        case YH_ISDIR:
            ndir++;
            break;
        case YH_STAT_FAIL:
            printf("%s get stat fail : %s\n", pathname, strerror(errno));
            return -2;
        case YH_OPEN_DIR_FAIL:
            printf("%s open dir fail : %s\n", pathname, strerror(errno));
            return -3;
        case YH_MEMORY_FAIL:
            printf("realloc fail, current level : %s\n", pathname);
            exit(1);
        case YH_CLOSE_DIR_FAIL:
            printf("close dir fail, current level : %s\n", pathname);
            return -5;
        default:
            return -6;
    }
    return 0;
}

static int recursivly_go_deep_from(const char *pathname) {
    
    struct stat st;
    if (lstat(pathname, &st) < 0)
        return __handle_one_file(pathname, &st, YH_STAT_FAIL);
    
    if (S_ISDIR(st.st_mode) == 0)
        return __handle_one_file(pathname, &st, YH_FILE);
    
    int ret = 0;
    if ((ret = __handle_one_file(pathname, &st, YH_ISDIR)) < 0)
        return ret;
    
    /* 不用再扩充数组以容纳路径，
       因为最大文件名是有限制的 MAX_NAME */
    
    DIR *dp = NULL;
    struct dirent *dir_ren = NULL;
    if ((dp = opendir(max_path_buf)) == NULL) {
        __handle_one_file(pathname, &st, YH_OPEN_DIR_FAIL);
    } else {
        /* 先打开目录文件，再切换工作目录，
           为什么呢？举例子：工作目录为 /usr/local/bin，打开 bin 目录会失败 */
        chdir(pathname);
        while ((dir_ren = readdir(dp)) != NULL) {
            if (strcmp(dir_ren->d_name, ".")  == 0 ||
                strcmp(dir_ren->d_name, "..") == 0)
                continue;
            strncpy(max_path_buf, dir_ren->d_name, strlen(dir_ren->d_name));
            max_path_buf[strlen(dir_ren->d_name)] = 0;
            if (recursivly_go_deep_from(max_path_buf) != 0)
                break;
        }
        chdir("..");
    }
    
    if (dp != NULL && closedir(dp) < 0)
        return __handle_one_file(pathname, &st, YH_CLOSE_DIR_FAIL);
    
    return 0;
}

int myftw(const char *pathname) {
    if (pathname == NULL) {
        printf("pathname is NULL!\n");
        return 1;
    }
    max_path_buf = malloc(MAX_NAME);
    max_path_len = MAX_NAME;
    strncpy(max_path_buf, pathname, strlen(pathname));
    max_path_buf[strlen(pathname)] = 0;
    int ret = recursivly_go_deep_from(pathname);
    free(max_path_buf);
    max_path_buf = NULL;
    max_path_len = 0;
    return ret;
}

void sig_int(int signo) {
    printf("\n【操作被打断！】\n"
           "目录 : %zd\n"
           "普通文件 : %zd\n"
           "fifo : %zd\n"
           "socket : %zd\n"
           "块特殊设备 : %zd\n"
           "字符特殊设备 : %zd\n"
           "符号链接 : %zd\n", ndir, nreg, nfifo, nsock, nblk, nchr, nlnk);
    exit(2);
}

void (*yh_signal(int signo, void (*sig_handler)(int))) (int) {
    struct sigaction new_act, old_act;
    new_act.sa_mask = 0;
    new_act.sa_handler = sig_handler;
    if (signo == SIGALRM) {
#ifdef SA_INTERRUPT
    new_act.sa_flags |= SA_INTERRUPT;
#endif
    } else {
        new_act.sa_flags |= SA_RESTART;
    }
    if (sigaction(signo, &new_act, &old_act) < 0)
        return SIG_ERR;
    return old_act.sa_handler;
}

int main(int argc, char *argv[]) {
    
    if (argc != 2) {
        printf("./a.out [beg_file_path]\n");
        exit(1);
    }
    
    setbuf(stdout, NULL);
    
    if (yh_signal(SIGINT, sig_int) == SIG_ERR) {
        perror("signal error");
        exit(1);
    }
    
    if (myftw(argv[1]) < 0) {
        printf("myftw fail\n");
        exit(1);
    }
    
    printf("目录 : %zd\n"
           "普通文件 : %zd\n"
           "fifo : %zd\n"
           "socket : %zd\n"
           "块特殊设备 : %zd\n"
           "字符特殊设备 : %zd\n"
           "符号链接 : %zd\n", ndir, nreg, nfifo, nsock, nblk, nchr, nlnk);
    
    return 0;
}