From:	George Foot <mert0407 AT sable DOT ox DOT ac DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Newbie question, everyone should know this I don't.
Date:	7 Nov 1997 13:30:38 GMT
Organization:	Oxford University, England
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Message-ID:	<63v55u$d7o$1@news.ox.ac.uk>
References:	<63ul58$ars$1 AT news DOT sas DOT ab DOT ca>
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To:	djgpp AT delorie DOT com
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On 7 Nov 1997 08:57:12 GMT in comp.os.msdos.djgpp
steven AT freenet DOT edmonton DOT ab DOT ca wrote:

: What's the difference between linking and compiling? I know what compiling
: is... but linking is uncharted territory for myself.

Compilation is turning your C source code into object files, which
contain machine code, data, symbol names, etc.  They're not
executable.  Linking is combining several object files, along with any
libraries needed (e.g. the standard C library), to produce a file
which can be executed.

The difference is only really apparent when you use several source
files and tell gcc explicitly to do the compiling/linking in two
stages; if you specify `-c', it will compile only, leaving you with a
.o object file for each .c or .cc source file.  Then you can call it
again, passing these .o files and suitable arguments, to get an
executable file.

gcc -c file1.c file2.c             (compiles only, creating file1.o and file2.o)
gcc file1.o file2.o -o output.exe  (links the two object files to form the executable)

-- 
Regards,

george DOT foot AT merton DOT oxford DOT ac DOT uk

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