[英]Read text file into char Array. C++ ifstream
我試圖將整個file.txt讀入一個char數組。 但有一些問題,建議請=]
ifstream infile;
infile.open("file.txt");
char getdata[10000]
while (!infile.eof()){
infile.getline(getdata,sizeof(infile));
// if i cout here it looks fine
//cout << getdata << endl;
}
//but this outputs the last half of the file + trash
for (int i=0; i<10000; i++){
cout << getdata[i]
}
std::ifstream infile;
infile.open("Textfile.txt", std::ios::binary);
infile.seekg(0, std::ios::end);
size_t file_size_in_byte = infile.tellg();
std::vector<char> data; // used to store text data
data.resize(file_size_in_byte);
infile.seekg(0, std::ios::beg);
infile.read(&data[0], file_size_in_byte);
使用std::string
:
std::string contents;
contents.assign(std::istreambuf_iterator<char>(infile),
std::istreambuf_iterator<char>());
如果您計划將整個文件吸入緩沖區,則無需逐行讀取。
char getdata[10000];
infile.read(getdata, sizeof getdata);
if (infile.eof())
{
// got the whole file...
size_t bytes_really_read = infile.gcount();
}
else if (infile.fail())
{
// some other error...
}
else
{
// getdata must be full, but the file is larger...
}
每次讀取新行時都會覆蓋舊行。 保留索引變量i並使用infile.read(getdata+i,1)
然后遞增i。
您可以使用Tony Delroy的答案並合並一個小函數來確定文件的大小,然后創建該大小的char
數組,如下所示:
//Code from Andro in the following question: https://stackoverflow.com/questions/5840148/how-can-i-get-a-files-size-in-c
int getFileSize(std::string filename) { // path to file
FILE *p_file = NULL;
p_file = fopen(filename.c_str(),"rb");
fseek(p_file,0,SEEK_END);
int size = ftell(p_file);
fclose(p_file);
return size;
}
然后你可以這樣做:
//Edited Code From Tony Delroy's Answer
char getdata[getFileSize("file.txt")];
infile.read(getdata, sizeof getdata);
if (infile.eof()) {
// got the whole file...
size_t bytes_really_read = infile.gcount();
}
else if (infile.fail()) {
// some other error...
}
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