With this commit all functions declared in libc.h have been renamed
with the "jehanne_" prefix. This is done for several reason:
- it removes conflicts during symbol resolution when linking
standard C libraries like newlib or musl
- it allows programs depending on a standard C library to directly
link to a library depending on our non standard libc (eg libsec).
To ease transiction two files are provided:
- sys/include/lib9.h that can be included instead of <libc.h> to use
the old names (via a simple set of macros)
- sys/src/lib/c/lib9.c that can be compiled with a program where the
macro provided by lib9.h are too dumb (see for example rc or grep).
In the kernel port/lib.h has been modified accordingly and some of
the functions it directly provides has been renamed too (eg malloc
in qmalloc.c and print in devcons.c).
Added wdir to devself and devproc:
- read '#0/wdir' to get the working directory of the calling process
NOTE that a read(fd, nil, -1) will return the negated length
of the working directory, just in case you want to
allocate the memory required
- read '/proc/n/wdir' to know the working directory of process n
(read(fd, nil, -1) still returns the negated length)
- write '#0/wdir' to change the working directory of the calling process
NOTE: no offset is allowed and the provided string must
be null terminated
- write '/proc/n/wdir' to change the working directory of process n
NOTE: no offset is allowed and the provided string must
be null terminated; moreover if another process change the working
directory change during the write, the current process will
receive an error.
In libc updated getwd() and chdir().
Also modified pwd to get advantage of the new file.
To test, run /arch/amd64/qa/kern/wdir.rc or simply try
% pwd
/usr/glenda
% echo -n /tmp > /proc/$pid/wdir
% pwd
/tmp
% cat '#0/wdir' && echo
/tmp
The expected use cases for wdir in devproc are rio and acme.
Also, note that we could theoretically remove the cd builtin
from rc and simply implement it as a rc function.
We don't do that to preserve rc portability to other OS.
Devself provides to each process access to its own structures.
So far it contains four files:
- pid
- ppid
- pipes used to implement pipe(2)
- segments used to implement segattach, segdetach and segfree
Giacomo Tesio