Read contents of text file.

[Jason Heyes]

How do you read the contents of a text file into a std::string? Does this
code use the right classes and functions for the job?

std::string s;
char c;
while (is.get(c))
s += c;

Thanks.

 

[James Daughtry]

Well, if you need the entire contents of the file in a single string,
your loop will work, though there are other ways of doing it. You could
use getline for example:

std::string file;
std::string line;

while (std::getline(is, line))
file += line;

Or you could use a stringstream and rdbuf:

std:stringstream oss;
oss << in.rdbuf();
std::string file = oss.str();

There's no 'right' way to do it, just try whatever comes to mind and
see if it does what you want and has acceptable performance.

 

[Jason Heyes]

Well, if you need the entire contents of the file in a single string,
your loop will work, though there are other ways of doing it. You could
use getline for example:

std::string file;
std::string line;

while (std::getline(is, line))
file += line;

Or you could use a stringstream and rdbuf:

std:stringstream oss;
oss << in.rdbuf();
std::string file = oss.str();

There's no 'right' way to do it, just try whatever comes to mind and
see if it does what you want and has acceptable performance.

Ok. I'll use my loop for the time being.

 

[Marcelo Pinto]

while (std::getline(is, line))

file += line;

I believe you should add the newline caracter at the end of each line:

while (std::getline(is, line))
file += line + "\n";

Good luck,

Marcelo Pinto

 

[Alex Vinokur]

How do you read the contents of a text file into a std::string? Does this
code use the right classes and functions for the job?

[snip]

Reading file to string (29 ways):
http://groups-beta.google.com/group/perfo/msg/530fae8e5e065030?hl=en

 

[James Daughtry]

It depends on how you plan to use it. For situations where the newline
would be needed, it's usually better to place each line in a container
of strings rather than one big string. I left the decision open since
the OP didn't specify how the string was going to be used.