chmod

[ami]

Hello everyone,

Can someone please tell me whether there is the equivalent of chmod in Standard C++, i.e. change permissions on a file ?

I don't really want to use the system command ?

I found that I can do :-

char fn[]="./temp.file";
FILE *stream;

if ((stream = fopen(fn, "w")) != NULL)
{
if (chmod(fn, S_IRGRP|S_IRWXU|S_IROTH ) != 0)
{
perror("chmod() error");
}
fclose(stream);
}

But the issue here is that I need to use the old fashioned way of reading a file line by line, rather than use fstream.

Can I cast from std::fstream to const char* ?

Many thanks.

[jonnin]

I do not really understand your question:

- chmod as you have it does not care what file type you used, it is operating off the file name!

-you did not use fstream, you used a FILE*

If you want to read a text file line by line, use ifstream and getline. Or read the entire file into a buffer if its small and split it up using string functions, based off the end of line markers.

You cannot convert from a file object to a char * safely and expect the char * to contain the file's data. You can read the whole file into an allocated char * or array. Or part of the file, all the way down to 1 char into a char variable.

Try again, what exactly are you wanting to do?

Here is how to read line by line:
ifstream ifs;
ifs.open(fn);
ifs.getline(buffer, max_length);
//buffer is a char* or unsigned char* you can use it directly, or poke it into a string, or you can read directly into a string variable (I am fairly sure).

[Danny]

There's no equivalent of chmod in standard C++. However, chmod is rather portable function. If and when the FleSystem library is added to standard C++ is hard to tell at this stage (it won't happpen in C++0x).