On Fri, Jan 9, 2015 at 3:47 PM, Michael Kerrisk (man-pages) <mtk.manpages@xxxxxxxxx> wrote: > On 11/24/2014 12:53 PM, David Drysdale wrote: >> Signed-off-by: David Drysdale <drysdale@xxxxxxxxxx> >> --- >> man2/execveat.2 | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 153 insertions(+) >> create mode 100644 man2/execveat.2 > > David, > > Thanks for the very nicely prepared man page. I've done > a few very light edits, and will release the version below > with the next man-pages release. Many thanks, one error (of mine) in 2 places pointed out below. > .TH EXECVEAT 2 2015-01-09 "Linux" "Linux Programmer's Manual" > .SH NAME > execveat \- execute program relative to a directory file descriptor > .SH SYNOPSIS > .B #include <unistd.h> > .sp > .BI "int execveat(int " dirfd ", const char *" pathname "," > .br > .BI " char *const " argv "[], char *const " envp "[]," > .br > .BI " int " flags ); > .SH DESCRIPTION > .\" commit 51f39a1f0cea1cacf8c787f652f26dfee9611874 > The > .BR execveat () > system call executes the program referred to by the combination of > .I dirfd > and > .IR pathname . > It operates in exactly the same way as > .BR execve (2), > except for the differences described in this manual page. > > If the pathname given in > .I pathname > is relative, then it is interpreted relative to the directory > referred to by the file descriptor > .I dirfd > (rather than relative to the current working directory of > the calling process, as is done by > .BR execve (2) > for a relative pathname). > > If > .I pathname > is relative and > .I dirfd > is the special value > .BR AT_FDCWD , > then > .I pathname > is interpreted relative to the current working > directory of the calling process (like > .BR execve (2)). > > If > .I pathname > is absolute, then > .I dirfd > is ignored. > > If > .I pathname > is an empty string and the > .BR AT_EMPTY_PATH > flag is specified, then the file descriptor > .I dirfd > specifies the file to be executed (i.e., > .IR dirfd > refers to an executable file, rather than a directory). > > The > .I flags > argument is a bit mask that can include zero or more of the following flags: > .TP > .BR AT_EMPTY_PATH > If > .I pathname > is an empty string, operate on the file referred to by > .IR dirfd > (which may have been obtained using the > .BR open (2) > .B O_PATH > flag). > .TP > .B AT_SYMLINK_NOFOLLOW > If the file identified by > .I dirfd > and a non-NULL > .I pathname > is a symbolic link, then the call fails with the error > .BR EINVAL . Apologies, I think this should be ELOOP. > .SH "RETURN VALUE" > On success, > .BR execveat () > does not return. On error \-1 is returned, and > .I errno > is set appropriately. > .SH ERRORS > The same errors that occur for > .BR execve (2) > can also occur for > .BR execveat (). > The following additional errors can occur for > .BR execveat (): > .TP > .B EBADF > .I dirfd > is not a valid file descriptor. > .TP > .B EINVAL ELOOP here too. > .I flags > includes > .BR AT_SYMLINK_NOFOLLOW > and the file identified by > .I dirfd > and a non-NULL > .I pathname > is a symbolic link. > .TP > .B EINVAL > Invalid flag specified in > .IR flags . > .TP > .B ENOENT > The program identified by > .I dirfd > and > .I pathname > requires the use of an interpreter program > (such as a script starting with "#!"), but the file descriptor > .I dirfd > was opened with the > .B O_CLOEXEC > flag, with the result that > the program file is inaccessible to the launched interpreter. > .TP > .B ENOTDIR > .I pathname > is relative and > .I dirfd > is a file descriptor referring to a file other than a directory. > .SH VERSIONS > .BR execveat () > was added to Linux in kernel 3.19. > GNU C library support is pending. > .\" FIXME . check for glibc support in a future release > .SH CONFORMING TO > The > .BR execveat () > system call is Linux-specific. > .SH NOTES > In addition to the reasons explained in > .BR openat (2), > the > .BR execveat () > system call is also needed to allow > .BR fexecve (3) > to be implemented on systems that do not have the > .I /proc > filesystem mounted. > .SH SEE ALSO > .BR execve (2), > .BR openat (2), > .BR fexecve (3) > > -- > Michael Kerrisk > Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ > Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
