Hi Yann,
Yann Sionneau wrote,
Hello,
About
https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=858ffad2170762…
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