%general-entities; ]> Multiarch Wrapper Create the source file: cat > multiarch_wrapper.c << "EOF" #define _GNU_SOURCE #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #ifndef DEF_SUFFIX # define DEF_SUFFIX "64" #endif int main(int argc, char **argv) { char *filename; char *suffix; if(!(suffix = getenv("USE_ARCH"))) if(!(suffix = getenv("BUILDENV"))) suffix = DEF_SUFFIX; if (asprintf(&filename, "%s-%s", argv[0], suffix) < 0) { perror(argv[0]); return -1; } int status = EXIT_FAILURE; pid_t pid = fork(); if (pid == 0) { execvp(filename, argv); perror(filename); } else if (pid < 0) { perror(argv[0]); } else { if (waitpid(pid, &status, 0) != pid) { status = EXIT_FAILURE; perror(argv[0]); } else { status = WEXITSTATUS(status); } } free(filename); return status; } EOF Compile and Install the Multiarch Wrapper: gcc ${BUILD64} multiarch_wrapper.c -o /usr/bin/multiarch_wrapper This multiarch wrapper is going to be used later on in the book with Perl. It will also be very useful outside of the base CLFS system. Create a testcase: echo 'echo "32bit Version"' > test-32 echo 'echo "64bit Version"' > test-64 chmod -v 755 test-32 test-64 ln -sv /usr/bin/multiarch_wrapper test Test the wrapper: USE_ARCH=32 ./test USE_ARCH=64 ./test The output of the above command should be: 32bit Version 64bit Version Remove the testcase source, binaries, and link: rm -v multiarch_wrapper.c test{,-32,-64} Installed programs multiarch_wrapper Short Descriptions multiarch_wrapper Will execute a different program based on the USE_ARCH variable. The USE_ARCH variable will be the suffix of the executed program. multiarch_wrapper