_GNU_SOURCE is the only one you should ever define yourself. __USE_GNU is defined internally through a mechanism in features.h (which is included by all other glibc headers) when _GNU_SOURCE is defined, and possibly under other conditions. Defining or undefining __USE_GNU yourself will badly break the glibc headers.
I was able to install libc6 2.17 in Debian Wheezy by editing the recommendations in perror’s answer: IMPORTANT You need to exit out of your display manager by pressing CTRL–ALT–F1. Then you can stop x (slim) with sudo /etc/init.d/slim stop (replace slim with mdm or lightdm or whatever) Add the following line to the file … Read more
Sorry, but some answers are incorrect on Linux with Glibc On Linux with a GNU Glibc, you can customize printf: you would call register_printf_function to e.g. define the meaning of %Y in your printf format strings. However, this behavior is Glibc specific, and might even become obsolete… I’m not sure I would recommend this approach! … Read more
The reasons given in other answers are correct, but they are not the most important reason. The most important reason why glibc should not be statically linked, is that it makes extensive internal use of dlopen, to load NSS (Name Service Switch) modules and iconv conversions. The modules themselves refer to C library functions. If … Read more
GNU libc is not designed to be statically linked. Important functions, e.g. gethostbyname and iconv, will malfunction or not work at all in a static binary. Arguably even worse, under some conditions a static binary will attempt to dynamically open and use libc.so.6, even though the whole point of static linkage is to avoid such … Read more
After trying some things, I finally managed to figure out how to do this. First of all, in glibc, malloc is defined as a weak symbol, which means that it can be overwritten by the application or a shared library. Hence, LD_PRELOAD is not necessarily needed. Instead, I implemented the following function in a shared … Read more
Yes there is, I’ve used a custom built glibc to install a JRE on it. You can find it here You can use wget or curl to get the code and apk to install them UPDATED commands see comments below apk –no-cache add ca-certificates wget wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub wget https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.28-r0/glibc-2.28-r0.apk apk add glibc-2.28-r0.apk … Read more
The only reliable and portable way to have the OS reclaim memory is to exit the process and restart it again, restoring any state you need to continue. Of course, writing your own malloc/free implementation using brk/sbrk according to your needs is the other option.
Setup 1: glibc without dedicated GCC This setup might work and is quick as it does not recompile the whole GCC toolchain, just glibc. The only problem I have with this setup is that I haven’t found a nice way to use runtime objects such as crt1.o, crti.o, and crtn.o provided by our glibc, and … Read more
I am surprised that there is a problem, but it does seem to be a problem on Linux (I tested on Ubuntu 16.04 LTS running in a VMWare Fusion VM on my Mac) — but it was not a problem on my Mac running macOS 10.13.4 (High Sierra), and I wouldn’t expect it to be … Read more