I've written a simple c++ program on Xcode, all contained within ONE FILE called huffmanGenerator.cpp. The program reads input from a file on the user's computer, and writes output to a file saved to their computer.
The instructor has asked us to create a makefile so that our programs compile and run with g++ OR gcc in Linux; however she never showed us how to do so, and when the class asked for help, her answer was we could figure it out.
I found many links online, but they're all very confusing as this is all new to me, and most of them fail to answer even the most basic questions like what kind of file should the makefile be? Is it a .txt? Should I just save one in word?
Please help do what the instructor won't, enlighten me. Thanks!
what kind of file should the makefile be?
It should be a plaintext file called Makefile or makefile. The reason the name matters is because when you run the make command, it looks for a file with this name by default for directions on how to compile your code. You can also name it whatever you want as long as you specify the name when you run it (make -f filename).
Is it a .txt?
No, it has no extension. Extensions don't mean that much in *nix.
Should I just save one in word? (Assume you mean Microsoft Word.)
No, definitely not. Whitespace (tabs/spaces/new lines) have meaning in these files, so you should use an editor that won't add formatting to the file. Something like pico/vi/etc.
Here is an example of a makefile, that I think does what you are asking.
# You can change your compiler to gcc / g++ here.
CC=g++
# Add whatever flags you want to use here.
CFLAGS=-c -Wall
all:
$(CC) $(CFLAGS) huffmanGenerator.cpp -o huffmanGenerator
#Use something like this to run `make clean` which deletes your object files, so you can do a fresh compile.
#clean:
# rm -rf *o huffmanGenerator
As a side note, you would be served well not to blame your professor for not spelling out everything for you. When you graduate, you will often be given tasks that have no other directions than a set of requirements and a deadline. You will need to figure it out. You could have easily made this make file by visiting http://mrbook.org/tutorials/make/ (search google for 'makefile tutorial').
The makefile should be called Makefile. It is just a text file.
You need a text editor. There are many to choose from, vim, emacs, nano, pico, ..., etc.
Open a command line and run, say
$ pico Makefile
Then you would enter the contents of the Makefile
all:
g++ -o huffmanGenerator huffmanGenerator.cpp
Save and exit and run make
$ make
Related
I have to submit a makefile for a project and I can't get it to work. I am trying to use the appropriate c++ 11 standard, execute project2,out, and run the cpp files in my src, but I keep getting the error "Nothing to be done for 'Makefile'."
#specify std=c++11 in your makefile
CXXFLAGS += -std=c++11
#Your executable should be named project2.out
main: g++ -o project2.out src/*.cpp
clean: del *.o
When asking questions please always cut and paste the exact command you typed and the exact output you got, properly formatted for SO (if you get a lot of output trim it down to the relevant parts which includes the command make invoked and at least the first few (not last!!) errors you get).
In this case, if you'd shown us what command you were running I'll bet it's this:
make Makefile
that's wrong. The arguments to make are not the makefile to use: they're the target you want to update. Here you've asked make to update your Makefile, but it already exists so make says "nothing to do".
Just run:
make
to build the default target, or make clean to build the clean target.
Once you get past this, you can begin to work on why your makefile may or may not work.
I have a bunch of C++ programs each in its own sub-directory. Each sub-directory has a single C++ program in several files -- a .h and a .cpp file for each class plus a main .cpp program. I want to compile each program placing the executable in the corresponding sub-directory. (I also want to run each program and redirect its output to a file that is placed in the corresponding sub-directory but if I can get the compilation to work, I shouldn't have a problem figuring out this part.)
I'm using the bash shell on a UNIX system (actually the UNIX emulator Cygwin that runs on top of Windows).
I've managed to find on the web, a short scrip for compiling one-file programs in the current directory but that's as far as I've gotten. That script is as follows.
for f in *.cpp;
do g++ -Wall -O2 "$f" -o "{f/.cpp/}";
done;
I would really appreciate it someone could help me out. I need to do this task on average once every two weeks (more like 8 weeks in a row, then not for 8 weeks, etc.)
Unless you're masochistic, use makefiles instead of shell scripts.
Since (apparently) each executable depends on all the .h and .cpp files in the same directory, the makefiles will be easy to write -- each will have something like:
whatever.exe: x.obj y.obj z.obj
g++ -o whatever.exe x.obj y.obj z.obj
You can also add a target in each to run the resulting executable:
run:
whatever.exe
With that you'll use make run to run the executable.
Then you'll (probably) want a makefile in the root directory that recursively makes the target in each subdirectory, then runs each (as described above).
This has a couple of good points -- primarily that it's actually built for this kind of task, so it actually does it well. Another is that it takes note of the timestamps on the files, so it only rebuilds the executables that actually need it (i.e., where at least one of the files that executable depends on has been modified since the executable itself was built).
Assuming you have a directory all of whose immediate subdirectories are all c++ programs, then use some variation on this...
for D in */; do cd "$D";
# then either call make or call your g++
# with whatever arguments in here
# or nest that script you found online if it seems to
# be doing the trick for you.
cd ../;
done;
That will move in to each directory, do its thing (whatever you want that to be) and then move back out.
I'm new to compiling C/C++ with the aid of make. I downloaded an open source project and noticed that there is in the make file CXXSources and CXXObjects. I think I understand roughly what the make file is doing with them but...
I don't have any of the source files listed under CXXSources. Are these like dependences I'm supposed to know how to find? Is there any custom as to what CXXSource is versus just Source?
Added link to project: http://www.fim.uni-passau.de/en/fim/faculty/chairs/theoretische-informatik/projects.html
More specifically, the GML parser, eg. http://www.fim.uni-passau.de/fileadmin/files/lehrstuhl/brandenburg/projekte/gml/gml-parser.tar.gz
It seems to be getting stuck on the line:
gml_to_graph : $(CXXOBJECTS) gml_scanner.o gml_parser.o
$(CXX) -o gml_to_graph_demo $(CXXOBJECTS) gml_parser.o gml_scanner.o -L$(LEDADIR)/lib -lG -lL -lm
The $CXXObjects is defined by
CXXSOURCES = gml_to_graph.cc gml_to_graph_demo.cc
CXXOBJECTS = $(CXXSOURCES:.cc=.o)
So I need gml_to_graph.cc, it seems. Or maybe I'm wrong?
Usually, the variables are set before the point where you see them. This could be
(a) via the environment
(b) before including the quoted makefile
(c) in the quoted makefile, but preceding the location quoted
To see (verbosely) what GNU make takes into account, do:
make -Bn
(it will show everything that _would get executed)
Even more verbose:
make -p all
It will show you all the internal variable expansions.
If you post a link or more information, we will be able to come up with less generic (and hence possibly less confusing) answers
I have a bunch of files in different folders:
/ai/client.cpp # contains the main function
/ai/utils/geometry.h
/ai/utils/geometry.cpp
/ai/world/world.h
/ai/world/world.cpp
/ai/world/ball.h
/ai/world/ball.cpp
/ai/world/bat.h
/ai/world/bat.cpp
How do I write a makefile to compile this program? I'm using Ubuntu.
Make is a versatile tool, and there are many different subtleties to using it. However, you can keep things simple:
OBJ := ai/utils/geometry.o ai/world/world.o ai/world/ball.o ai/world/bat.o
all: ai/client
.PHONY: all # specific to GNU make, which is what Ubuntu provides
ai/client: ai/client.o $OBJ
# this rule means each .cpp file depends on its corresponding header
# and, since the .o files depend on .cpp files (a builtin make rule),
# they will be recompiled if the headers change
#
# you can also get more complex and generate dependencies automatically
# look at the -MM option for gcc, for example
%.cpp: %.h
you should check out that you have installed g++ and build-essential
here is some insight into the makefile black magic consorsium
I think that make1 is directory aware so typing mydirectory/myfile.cpp should work well
the rest is basic g++ commands but the tutorial on 1 should be enough :)
1 the program that executes makefiles
its working thank you every1 for your valuable comments
specially for the links
on the previous post i forgot to write the client.cpp file on line 6
but my mistake was that i had included one header with a mistake in the client.cpp and it could never find it.
First result in google: http://www.opussoftware.com/tutorial/TutMakefile.htm
Seems to be a pretty good tutorial. Should be pretty simple to understand, note that they talk about the GNU version of make, which is what is most commonly used. There is also the BSD version though if you use a BSD-based OS(such as OpenBSD, NetBSD, or FreeBSD.. anyone know about Mac OSX?)
I'd like to compile cpp file w/o turning off vi.
I know the :!g++ file.cpp but I prefer :make so I added this line in .vimrc file
au FileType C set makeprg=gcc\ %
au FileType Cpp set makeprg=g++\ %
but I keep getting
"make: ***** No targets specified and no makefile found. Stop.** "message.
can anyone tell me what is wrong with my setting?
I use to compile successfully with the option above.
You need the substitution there, try something like:
set makeprg=gmake\ %:r.o
Oh, this assumes that you've got:
a (M|m)akefile in the directory, or
default SUFFIX rules are available for your environment (which it looks like there aren't)
Check for the default by entering:
make -n <my_file>.o
and see if that gives you something sensible.
If there is a makefile in another location you can add the -f option to point at the makefile, for example:
set makeprg=gmake\ -f\ ../some_other_dir/makefile\ %:r.o
BTW For learning about make, and especially gmake, I'd suggest having a look at the excellent book "Managing Projects with GNU Make" (sanitised Amazon link).
HTH.
cheers
I should change C,Cpp into c,cpp, then it works fine.
thank you all, especially Rob Wells, your answer helped me a lot. thank you.
I think it's much easier if you write a Makefile and put it where vi can find it. I'm not sure if you actually use vi (I've only used Vim), but when there is a Makefile compiling should be as easy as writing :make (no set makeprg needed).
It can be easily achieved by the use of key maps.
First open up your vimrc file and these lines to the file,
autocmd filetype cpp nnoremap <F4> :!g++ % -ggdb -o %:r <CR>
autocmd filetype cpp nnoremap<F5> :!g++ % -ggdb -o %:r && ./%:r <CR>
The first line maps the key F4 to compiling the file. The second line maps the key F5 to compile and run.
If you use gdb frequently then this may also come handy.
autocmd filetype cpp nnoremap<F10> :!g++ % -ggdb -o %:r && gdb -tui %:r <CR>
This line maps the key F10 to compile and start gdb
Hope this helps.
I recommend a vim plugin called SingleCompile instead of what you have done:
http://www.vim.org/scripts/script.php?script_id=3115
First of all, just make the bloody make file. Every tool out there is expecting to work with make and if your compilations are that simple it takes about 30 seconds to write a make file that compiles all c and cpp files into an executable.
Second, if you refuse to use a make file then try
:help system
That should give you enough info to come up with your own command similar to this
:com Mymake call system("g++ ".expand("%"))