| Title: | DECC |
| Notice: | General DEC C discussions |
| Moderator: | TLE::D_SMITH N TE |
| Created: | Fri Nov 13 1992 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 2212 |
| Total number of notes: | 11045 |
Now I'm sure this is a really dumm question, but I'll ask anyways!
When I write a c program on VMS (just a hello world or something) the
size is 1 block, compile/link it and it comes to 4 blocks. OK.
Why when I do the same thing on Digital Unix (version doesn't seem to
make any difference) is the size diference soo much bigger?
cfacs_fm> cc -o hello hello.c
cfacs_fm> ls -l hello*
-rwxrwxr-x 1 fm users 24576 May 14 12:32 hello
-rw-rw-r-- 1 fm users 57 May 14 12:32 hello.c
cfacs_fm> cat hello.c
#include <stdio.h>
main()
{
printf("Hello world\n");
}
Am I missing something ragingly obvious here, or is it just how Unix
is???
Alen.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 2187.1 | perhaps a private copy is the default? | CUJO::SAMPSON | Wed May 14 1997 11:07 | 3 | |
Just a guess, but maybe the default on Digital UNIX is to pull in all
of the object code needed for a printf()? That is, maybe it would help
to specify the appropriate sharable library?
| |||||
| 2187.2 | Looks like minimum exe file size is larger on D.Unix | SUBPAC::FARICELLI | Wed May 14 1997 12:11 | 23 | |
If you do a "size" of the hello executable, you will see: uogsrv-37> size hello text data bss dec hex 8192 8192 0 16384 4000 Looks like the minimum size of the text and data for an executable on Alpha/Unix is 8192 (same as the page size, suprise suprise). If you use the 'strip' command to delete the symbol table and relocation bits in the executable, the file size decreases to 16384, which is exactly 2*8192. In other words, the minimum executable file size appears to be larger for Alpha/Digital Unix than for Alpha/OpenVMS. FWIW, one of my large programs is 1482752 bytes on Alpha/Digital Unix, but 1587712 bytes on Alpha/OpenVMS. So there ;-) FWIW, regarding reply .1, -call_shared is the default (that is, shared libs are used by default). -- John Faricelli | |||||
| 2187.3 | DECCXL::OUELLETTE | mudseason into blackfly season | Wed May 14 1997 18:09 | 9 | |
You also need to consider the difference between the image activator on VMS and exec on Unix. Unix more or less memory maps the file, relocates the parts with relocations and jumps into the program. VMS's image activation does a bit more unpacking for you and so may not need a full page of disk image for what will eventually be the $CODE$ section of the program... Speculation on my part. The 2 page minimum on Unix is pretty clear though. One page for .text one page for .data. R. | |||||