This is a C preprocessor question: How to convert a shell command which outputs a string with whitespaces within it into a valid preprocessor token?
I have this program:
And I try to compile it using:Code:int main() { printf("%s\n", GCCVERSION); }
% gcc -DGCCVERSION="\"`gcc --version`\"" testver.c
Unmatched ".
FYI:
% gcc --version
gcc (GCC) 3.4.4
Copyright (C) 2004 Free Software Foundation, Inc. ....
I appreciate your help.
It's getting confused by the newline characters that are output as part of the gcc --version command. Here's one solution:
If you want to see what is going on during the preprocessing stage, use the -E flag on the main gcc call:Code:$ gcc -DGCCVERSION="\"$(gcc --version|tr '\n' ' ')\"" junk1.c $ ./a gcc (GCC) 3.4.4 (cygming special) (gdc 0.12, using dmd 0.125) Copyright (C) 2004 Free Software Found ation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Code:$ gcc -DGCCVERSION="\"$(gcc --version|tr '\n' ' ')\"" -E junk1.c ... int main() { printf("%s\n", "gcc (GCC) 3.4.4 (cygming special) (gdc 0.12, using dmd 0.125) Copyright (C) 2004 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. "); }
When all else fails, read the instructions.
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Does not work in my system:
% gcc -DGCCVERSION="\"$(gcc --version | tr '\n' ' ' ) \"" test.c
Illegal variable name.
My gcc is 3.4.4.
And I thought CPP was confused by the blank between "gcc" and "(GCC)", and the blank between "(GCC)" and "3.4.4".
Last edited by hzmonte; 10-26-2005 at 06:48 PM. Reason: correct the gcc version - 3.4.4
It depends on what shell you're using. What shell are you using? The above works on bash/zsh, but fails on csh/tcsh. It is likely you are using tcsh.
tcsh.
Can someone suggest something that can work in tcsh? Many thanks.
OK, since nobody had any suggestion about making it work with tcsh, I am giving up on that. My new question is: How can I incorporate a (bash) shell command in a GNU Makefile?
Same as before, my program is this:
It is OK for me to do this:Code:int main() { printf("%s\n", GCCVERSION); }
But if I write a Makefile like this:Code:bash-2.05$ gcc -DGCCVERSION="\"$(gcc --version |head -1)\"" testver.c bash-2.05$ a.out gcc (GCC) 3.4.4
It won't work:Code:a.out: testver.c gcc -DGCCVERSION="\"$(gcc --version |head -1)\"" testver.c
What's wrong? Thank you.Code:bash-2.05$ make gcc -DGCCVERSION="\"\"" testver.c bash-2.05$ a.out
Make does shell interpolation differently, this should work:
And I expect nobody offered a way in tcsh because nobody uses tcshCode:a.out: testver.c gcc -DGCCVERSION="\"$(shell gcc --version | head -1)\"" testver.c
