APUE-4.3打印文件类型

创建文件4.3_file_types.c，内容为

#include <sys/types.h>
#include <sys/stat.h>
#include "apue.h"
int main(int argc, char *argv[]) {
    int i;
    struct stat buf;
    char *ptr;
    for (i = 1; i < argc; i++) {
        printf("%s: ", argv[i]);
        if (lstat(argv[i], &buf) < 0) {
            err_ret("lstat error");
            continue;
        }
        if (S_ISREG(buf.st_mode)) ptr = "regular";
        else if (S_ISDIR(buf.st_mode)) ptr = "directory";
        else if (S_ISCHR(buf.st_mode)) ptr = "character special";
        else if (S_ISBLK(buf.st_mode)) ptr = "block special";
        else if (S_ISFIFO(buf.st_mode)) ptr = "fifo";
#ifdef S_ISLNK
        else if (S_ISLNK(buf.st_mode))ptr = "symbolic link";
#endif
#ifdef S_ISSOCK
        else if (S_ISSOCK(buf.st_mode)) ptr = "socket";
#endif
        else ptr = "** unknown mode **";
        printf("%s\n", ptr);
    }
    exit(0);
}

编译

gcc 4.3_file_types.c -o 4.3_file_types -lapue

运行

./4.3_file_types /etc/passwd /etc /etc/log /dev/tty /var/lib/oprofile/opd_pipe /dev/sr0 /dev/cdrom

运行结果为：