Allocating zero size memory results in implementation-defined behavior:
man:malloc(3) :
If size is 0, then malloc() returns either NULL, or a unique pointer
value that can later be successfully passed to free().
htop is a cross-platform interactive process viewer.
htop allows scrolling the list of processes vertically and horizontally to see their full command lines and related information like memory and CPU consumption.
The information displayed is configurable through a graphical setup and can be sorted and filtered interactively.
Tasks related to processes (e.g. killing and renicing) can be done without entering their PIDs.
Running htop requires ncurses libraries (typically named libncursesw*).
For more information and details on how to contribute to htop visit htop.dev.
Build instructions
This program is distributed as a standard GNU autotools-based package.
Compiling htop requires the header files for ncurses (libncursesw*-dev). Install these and other required packages for C development from your package manager.
Alternatively, for compiling sources downloaded from the Git repository (git clone or downloads from Github releases),
install the header files for ncurses (libncursesw*-dev) and other required development packages from your distribution's package manager. Then run:
./autogen.sh && ./configure && make
By default make install will install into /usr/local, for changing the path use ./configure --prefix=/some/path.
See the manual page (man htop) or the on-line help ('F1' or 'h' inside htop) for a list of supported key commands.
Support
If you have trouble running htop please consult your Operating System / Linux distribution documentation for getting support and filing bugs.
Bugs, development feedback
We have a development mailing list. Feel free to subscribe for release announcements or asking questions on the development of htop.
You can also join our IRC channel #htop on freenode and talk to the developers there.
If you have found an issue with the source of htop, please check whether this has already been reported in our Github issue tracker.
If not, please file a new issue describing the problem you have found, the location in the source code you are referring to and a possible fix.
History
htop was invented, developed and maintained by Hisham Muhammad from 2004 to 2019. His legacy repository has been archived to preserve the history.
In 2020 a team took over the development amicably and continues to maintain htop collaboratively.
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