On Thu, Sep 3, 2009 at 12:06 AM, narendra babu<[email protected]> wrote: > > hi , > > I have lot of makefiles , by default gcc geneartes 64 bit executable on 64 > machine but i need to change to 32 bit , dont want to change the makefiles .
Ok. > Instead is there anyway i can change default flags at command line for gcc I think there is. > Can i set environment variable > export CFLAGS=-m32 CXX=-m32 so that by gcc takes CFLAGS or CXX to generate > 32bit code instead of 64 bit code by default . I dunno which one gets preference. You have to check and read the documentation on GNU Make. If the Makefile CFLAGS takes preference then you will have no choice but to modify it in all Makefiles. I will give you a command by which you can do it in one stroke. Typically CFLAGS will already be used in Makefiles. So you want to add to it. I am assuming here that you are not having any flag that will reset this -m32 or whatever flag you want to set. Then this command will change all files at one go. $ vim -p foo/Makefile ba/Makefile foo/bar/Makefile Inside vim enter this command: :tabdo :%s/CFLAGS=/CFLAGS+=-m32/g If this command goes through then you can save all files and exit at one stroke with :tabdo wq Please remember that you may not get the same results I expect. You should follow along these lines. If you don't like tabbed vim, you could go for :bufdo if you use vi or vim without -p flag. That should give the same results too. > > So in simple i want to chnage the gcc default flag settings > > Like $CFLAGS=-m32 gcc hello.c should generate me 32 bit code on a 64 bit > machine instead of 64 bit . I dunno this. I have never used a 64 bit machine. > Note : As by default all my makefiles can take the default CFLAGS which is > set as environment variable . > I guess so. -Girish -- Gayatri Hitech web: http://gayatri-hitech.com SpamCheetah Spam filter: http://spam-cheetah.com _______________________________________________ To unsubscribe, email [email protected] with "unsubscribe <password> <address>" in the subject or body of the message. http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
