Hi Yann, Yann Sionneau wrote,

Hello,

About https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=858ffad21707622...

I'm not sure why exactly sizeof(int)*3 in the following line:

char buf[sizeof "/proc/self/fd/" + sizeof (int) * 3];

IIUC, this is supposed to give room for the ascii decimal representation of the file descriptor number.

Maybe we could read the max file descriptor number configured in the kernel from "/proc/sys/fs/file-max" (or "/proc/sys/file-max" for old systems?).

So:

1/ fopen("/proc/sys/fs/file-max", "r");

2/ fscanf(fp, "%d", &fdmax);

3/ fdmax_length = log10(fdmax);

Then use fdmax_length

Or, much simpler: take for granted that fd is always an int, and thus max 32 bits, and hard code that max "string length" of a file descriptor is 10 chars.

But in any case maybe add a comment on top of the line to explain the "magic number".

I checked with glibc/musl and both seems to use this magic number for granted. Could you sent a patch with a comment to the existing code?

best regards Waldemar