lstat(传入路径参数，&一种struct)返回0或1
apue 04.pdf
S _ I S L N K ( )
S _ I S S O C K ( )
符号连接( P O S I X . 1 或 S V R 4无此类型) 套接字( P O S I X . 1 或 S V R 4无此类型)
为了跨平台，代码写成#ifdef这种
#include "apue.h"intmain(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);}