好的，所以我正在尝试创建一个文件浏览器程序，我现在已经掌握了基础知识，但这一行在这里：
fprintf(stderr, "stat returned %i\n", stat(files[curser].c_str(), &st));
说stat正在返回-1（失败），我想知道为什么。有人能告诉我吗？以下是完整的资料来源：
#include <SDL/sdl.h>
#include <SDL/sdl_image.h>
#include <SDL/SDL_audio.h>
#include <SDL/SDL_mixer.h>
#include <SDL/SDL_ttf.h>
#include <iostream>
#include <sstream> // String stream library
#include <string>
#include <stdio.h>
#include <vector>
#include <fstream>
#include <ios>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#define TICK_INTERVAL 30
using namespace std;
extern "C" int SDL_main(int argc, char *argv[]);
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 16;
SDL_Surface *screen = NULL;
SDL_Surface *message = NULL;
bool keys[322];
TTF_Font *font = NULL;
SDL_Color textColor = { 255, 255, 255};
SDL_Color highlightColor = { 255, 0, 0};
Uint32 TimeLeft(void)
{
static Uint32 next_time = 0;
Uint32 now;
now = SDL_GetTicks();
if ( next_time <= now ) {
next_time = now+TICK_INTERVAL;
return(0);
}
return(next_time-now);
}
void init(){
// initialize SDL video. If there was an error SDL shows it on the screen
if ( SDL_Init( SDL_INIT_EVERYTHING) < 0 )
{
fprintf(stderr, "Unable to init SDL: %s\n", SDL_GetError() );
SDL_Delay( 5000 );
// exit(EXIT_FAILURE);
}
// make sure SDL cleans up before exit
atexit(SDL_Quit);
SDL_ShowCursor(SDL_DISABLE);
// create a new window
screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_DOUBLEBUF|SDL_HWSURFACE );
if ( !screen )
{
fprintf(stderr, "Unable to set video: %s\n", SDL_GetError());
SDL_Delay( 5000 );
// exit(EXIT_FAILURE);
}
SDL_WM_SetCaption("Dir Reader", "Dir Reader");
TTF_Init();
//SDL_JoystickEventState(SDL_ENABLE);
// joystick = SDL_JoystickOpen(0);
}
void cleanup(){
// we have to quit SDL
SDL_Quit();
exit(EXIT_SUCCESS);
}
void apply_surface ( int x, int y, SDL_Surface* source, SDL_Surface* destination ){
// make a temporary rectangle to hold the offsets
SDL_Rect offset;
// give the offsets to the rectangle
offset.x = x;
offset.y = y;
// blit the surface
SDL_BlitSurface( source, NULL, destination, &offset );
}
void apply_surface ( int sourceX, int sourceY, int x, int y, SDL_Surface* source, SDL_Surface* destination ){
// make a temporary rectangle to hold the offsets
SDL_Rect offset;
SDL_Rect sourceRect;
// give the offsets to the rectangle
offset.x = x;
offset.y = y;
sourceRect.x = sourceX;
sourceRect.y = sourceY;
sourceRect.h = source->h;
sourceRect.w = source->w;
// blit the surface
SDL_BlitSurface( source, &sourceRect, destination, &offset );
}
void apply_surface ( int sourceX, int sourceY, int sourceW, int sourceH, int x, int y, SDL_Surface* source, SDL_Surface* destination ){
// make a temporary rectangle to hold the offsets
SDL_Rect offset;
SDL_Rect sourceRect;
// give the offsets to the rectangle
offset.x = x;
offset.y = y;
sourceRect.x = sourceX;
sourceRect.y = sourceY;
sourceRect.h = sourceH;
sourceRect.w = sourceW;
// blit the surface
SDL_BlitSurface( source, &sourceRect, destination, &offset );
}
int getdir (string dir, vector<string> &files)
{
DIR *dp;
struct dirent *dirp;
if((dp = opendir(dir.c_str())) == NULL) {
cout << "Error(" << errno << ") opening " << dir << endl;
return errno;
}
while ((dirp = readdir(dp)) != NULL) {
files.push_back(string(dirp->d_name));
}
closedir(dp);
return 1337;
}
int SDL_main( int argc, char* argv[] )
{
printf("init.\n");
init();
font = TTF_OpenFont( "GOODTIME.ttf", 15 );
bool done = false;
string dir = "C:/";
// dir = dir.substr(0, dir.size() - 1);
int curser = 0;
while(!done){
vector<string> files = vector<string>();
if(getdir(dir,files) == errno){
printf("error number: %i.\n", errno);
}
SDL_Event event;
while (SDL_PollEvent(&event))
{
// Close window : exit
if( event.type == SDL_QUIT )
done = true ;
else if (event.type == SDL_KEYDOWN )
{
keys[event.key.keysym.sym] = true;
}
else if (event.type == SDL_KEYUP )
{
keys[event.key.keysym.sym] = false;
}
}
if (keys[SDLK_x]){
struct stat st;
fprintf(stderr, "stat returned %i\n", stat(files[curser].c_str(), &st));
if(S_ISDIR(st.st_mode)){
if(files[curser][0] == '.' && files[curser][1] == '.'){
dir = dir.substr(0, dir.size() - 1);
dir = dir.substr(0, dir.find_last_of('/'));
}
else{
string temp = string(files[curser]);
dir += "/";
dir += temp;
}
}
curser = 1;
keys[SDLK_x] = false;
}
if (keys[SDLK_UP]){
curser--;
if(curser <= 0){
curser = (int) (files.size() - 1);
}
keys[SDLK_UP] = false;
}
if (keys[SDLK_DOWN]){
curser++;
if(curser >= (int) files.size()){
curser = 1;
}
keys[SDLK_DOWN] = false;
}
SDL_Rect rect;
rect.x = 0;
rect.y = 0;
rect.h = 480;
rect.w = 640;
SDL_FillRect(screen, &rect, 0x000000);
message = TTF_RenderText_Solid( font, dir.c_str(), textColor );
apply_surface(0, 0, message, screen);
for(int i = 0; i < (int) files.size(); i++){
if(curser == i){
message = TTF_RenderText_Solid( font, files[i].c_str(), highlightColor );
}
else{
message = TTF_RenderText_Solid( font, files[i].c_str(), textColor );
}
apply_surface(0, 25 + (i * 15), message, screen);
}
SDL_Delay(TimeLeft());
SDL_Flip(screen);
}
cleanup();
return 0;
}
答案 0 :(得分：2)
是的，实际上你可以告诉自己。如果stat失败，则会设置errno变量以指明原因。你只需要找出它的设定。您可能还希望确保files[curser].c_str()本身有效，即使您已将其设置为"c:\"。
即使是您所说的内容，也可能stat不喜欢在该表单中的根目录上工作。这将取决于您正在使用的实现（您应该将其添加为标记）。
换句话说，将您的行改为：
int x = stat(files[curser].c_str(), &st);
fprintf(stderr, "stat returned %d '%s' %d\n", x, files[curser].c_str(), errno);
对于它的价值（并且可能不多），以下程序在VS2008下工作正常：
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
int main(int argc, char* argv[]) {
struct stat st;
int x = stat("c:\\", &st);
fprintf(stderr, "stat returned %d %d\n", x, errno);
return 0;
}
输出：
stat returned 0 0