Re: gcc

[Adam Stiles <adam@priceengines.co.uk>]

On Wednesday 07 June 2006 20:06, Francesco Pietra wrote:
> Yes, it was compiled OK. However, because make was from root, the property
> of all compiled *.o files is root root. This makes some problems in the use
> of the program, such as in deleting files.
>
> Issuing
>
> ln -s /usr/bin/gcc-41 /usr/local/bin/gcc
>
> either as $ or #, followed by
>
> $ make
>
> reports
> gcc -g -02 -c -o active.o active.c
> cc1: error: active.c: Permission denied
> make: *** [active.o] Error 1
>
> Perhaps, unless link/make can be arranged differently, the easiest would be
> to change the property of all *.o files. Don'y remember how this could be
> done with a single command.

When you do
# make install
all the important files are copied somewhere sensible, usually /usr/local/bin 
which is in the standard path and out of reach of the package management 
system.  You have to be root to do this, because ordinary users really should 
not be writing to such places.

If `make install` is not working, then that indicates an error  {as opposed to 
a warning; errors are serious enough actually to stop the compilation}  
somewhere.  So you probably want to capture the full output to analyse at 
your leisure.  Type
$ script [filename]
to begin capturing the terminal output into a file  {if you don't give a 
filename the default will be 'typescript'};  then
$ make
to start the make process.  Press ctrl+D at the end, to stop writing to the 
script file and save it.

Now you can look through the file with an editor and see where the error 
occurred.

> Incidentally, in previous compilation the proprty of *.c files was
> francesco francesco. Now it is 500 500; I imagine that 500 stands for
> francesco. True? You know, when such affaris are carried out sporadically,
> memory about tends to vanish to make room to other storage.

Unix stores the users and groups associated with files numerically, and looks 
them up for display.  It's conventional that the low numbers are used for 
system users and "artificial" users, and higher numbers are the "real" users.  
On Red Hat systems and derivatives, non-system users start at 500; on Debian 
systems, non-system users start at 1000.

What probably happened is that someone generated the tarball as the first 
non-system user on a Red Hat-ish system, who would have been numbered 500.  
One of the times that you extracted it, you took over ownership of the files; 
the other time, you preserved the original file ownerships  {perhaps you 
extracted it as root or something}.  Your Debian system doesn't have a user 
#500, so it can't give you a username.

Not that it matters much because only root can do `make install`, and root can 
always read files belonging to anyone regardless of permission modes.

-- 
AJS