将文本文件读入字符数组。C++ ifstream
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原文地址: http://stackoverflow.com/questions/4373047/
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Read text file into char Array. C++ ifstream
提问by nubme
Im trying to read the whole file.txt into a char array. But having some issues, suggestions please =]
我试图将整个 file.txt 读入一个字符数组。但是有一些问题，请提出建议=]
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]
}
采纳答案by tmiddlet
Every time you read a new line you overwrite the old one. Keep an index variable i and use infile.read(getdata+i,1)then increment i.
每次阅读新行时，都会覆盖旧行。保留一个索引变量 i 并使用infile.read(getdata+i,1)然后增加 i。
回答by Vertexwahn
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);
回答by 0x499602D2
Use std::string:
使用std::string：
std::string contents;
contents.assign(std::istreambuf_iterator<char>(infile),
std::istreambuf_iterator<char>());
回答by Tony Delroy
You don't need to read line by line if you're planning to suck the entire file into a buffer.
如果您打算将整个文件放入缓冲区，则无需逐行读取。
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...
}
回答by Victor Resnov
You could use Tony Delroy's answer and incorporate a little function to determine the size of the file, and then create the chararray of that size, like this:
您可以使用 Tony Delroy 的答案并结合一个小函数来确定文件的大小，然后创建该char大小的数组，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;
}
Then you can do this:
然后你可以这样做：
//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...
}
