Hi everyone,

I must be ignoring something really basic but please anyone tell me what is the problem with the following code. Its a simple program to create a temporary file containing all command line arguments one per line (seperated by CRLFs). The code compiles fine in VC++ but when the generated exe is run, it creates the file with command line arguments seperated by CRCRLFs (\r\r\n) instead of CRLFs (\r\n).


#include <stdio.h>

main(int argc, char *argv[])
{
FILE *f;
int i;
char g[] = "C:\\temp\\XXXXXX";
char *h;
char *mktemp();
h = mktemp(g);

f = fopen(h, "w");
for(i=0;i<argc;i++)
{
fputs(argv[i], f);
fputs("\r\n", f);
}
fclose(f);
}

Regards,
Akash

It seems using "wb" in place of "w" for fopen solved the problem but i am still wondering why this different behaviour for binary files.

Various OS's have different conventions for what defines a "newline".
Unix - \n
Windows \r\n
Mac \r

In binary mode what you write is what you get; there is no automatic translation of newlines going on, which is likely what you are experiencing.

Some higher level languages (Python for example) do automatic newline translation depending on OS -- in your apps you always represent the newline as \n and files written will adapt to the underlying OS.

"In binary mode what you write is what you get; there is no automatic translation of newlines going on, which is likely what you are experiencing"

Thanks

Mac \r

Your information is several years out of date.

Your information is several years out of date.

If you wish to be pedantic then I have to point out that my information isn't out of date, just not specific. I could have been more specific and added that my reference to "Mac" meant Mac OS < X, since "Unix" includes Mac OS >= X.

There are still a goodly number of machines running Mac OS < X.

It seems using "wb" in place of "w" for fopen solved the problem but i am still wondering why this different behaviour for binary files.

When you're writing in ASCII mode, Windows is converting your \n to \r\n. Since you're writing \r\n, Windows makes it \r\r\n