Hi Nora, On 6/24/21 10:42 PM, Nora Platiel wrote: > Hello, > I'm reporting a problem with the execve(2) man page (see the "absolute pathname" part): > >> If the pathname argument of execve() specifies an interpreter >> script, then interpreter will be invoked with the following >> arguments: >> >> interpreter [optional-arg] pathname arg... >> >> where pathname is the absolute pathname of the file specified as >> ^^^^^^^^^^^^^^^^^ >> the first argument of execve(), and arg... is the series of >> words pointed to by the argv argument of execve(), starting at >> argv[1]. Note that there is no way to get the argv[0] that was >> passed to the execve() call. > > Then in the final example: > >> $ ./execve ./script >> argv[0]: ./myecho >> argv[1]: script-arg >> argv[2]: ./script >> argv[3]: hello >> argv[4]: world > > According to the description, argv[2] is supposed to be the *absolute pathname* of "./script" but it is not. > (In path_resolution(7), an absolute pathname is defined to be a pathname starting with a '/' character.) > > I tested the example with kernel 4.4.246 and the output is the same as the one in the man page (relative paths are preserved). > I don't know about newer kernels, but if I understand correctly, either the "absolute pathname" wording is incorrect or the example is. > (In the latter case, perhaps the man page could also mention the change in behavior.) > > The "absolute pathname" wording was introduced here: > https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=60f16bf2fe6bd2d2d001d0a41936e778b1e7e3f6 > https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=63059c4b527d0da73666da5ff29dcc902e219371 Thanks for all of the info and links. I think you're right. In fact, POSIX talks about pathname, and not absolute pathname (<https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html>). However, the kernel documentation talks about 'full path', so I'm not sure if maybe some versions of the kernel did not support relative paths (<https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html>). I added Shawn to the thread, so maybe he can shed some light (he added that text). Regards, Alex -- Alejandro Colomar Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/
