mirror of https://github.com/mkerrisk/man-pages
execveat.2: Initial man page for execveat(2)
Signed-off-by: David Drysdale <drysdale@google.com> Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
David Drysdale
Michael Kerrisk
parent
c17d5bac2e
commit
53652782ae
|
|
@ -0,0 +1,153 @@
|
|||
.\" Copyright (c) 2014 Google, Inc.
|
||||
.\"
|
||||
.\" %%%LICENSE_START(VERBATIM)
|
||||
.\" Permission is granted to make and distribute verbatim copies of this
|
||||
.\" manual provided the copyright notice and this permission notice are
|
||||
.\" preserved on all copies.
|
||||
.\"
|
||||
.\" Permission is granted to copy and distribute modified versions of this
|
||||
.\" manual under the conditions for verbatim copying, provided that the
|
||||
.\" entire resulting derived work is distributed under the terms of a
|
||||
.\" permission notice identical to this one.
|
||||
.\"
|
||||
.\" Since the Linux kernel and libraries are constantly changing, this
|
||||
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
||||
.\" responsibility for errors or omissions, or for damages resulting from
|
||||
.\" the use of the information contained herein. The author(s) may not
|
||||
.\" have taken the same level of care in the production of this manual,
|
||||
.\" which is licensed free of charge, as they might when working
|
||||
.\" professionally.
|
||||
.\"
|
||||
.\" Formatted or processed versions of this manual, if unaccompanied by
|
||||
.\" the source, must acknowledge the copyright and authors of this work.
|
||||
.\" %%%LICENSE_END
|
||||
.\"
|
||||
.TH EXECVEAT 2 2014-04-02 "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 " fd ", const char *" pathname ","
|
||||
.br
|
||||
.BI " char *const " argv "[], char *const " envp "[],"
|
||||
.br
|
||||
.BI " int " flags);
|
||||
.SH DESCRIPTION
|
||||
The
|
||||
.BR execveat ()
|
||||
system call executes the program pointed to by the combination of \fIfd\fP and \fIpathname\fP.
|
||||
The
|
||||
.BR execveat ()
|
||||
system call 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 fd
|
||||
(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 fd
|
||||
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 fd
|
||||
is ignored.
|
||||
|
||||
If
|
||||
.I pathname
|
||||
is an empty string and the
|
||||
.BR AT_EMPTY_PATH
|
||||
flag is specified, then the file descriptor
|
||||
.I fd
|
||||
specifies the file to be executed.
|
||||
|
||||
.I flags
|
||||
can either be 0, or include the following flags:
|
||||
.TP
|
||||
.BR AT_EMPTY_PATH
|
||||
If
|
||||
.I pathname
|
||||
is an empty string, operate on the file referred to by
|
||||
.IR fd
|
||||
(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 fd
|
||||
and a non-NULL
|
||||
.I pathname
|
||||
is a symbolic link, then the call fails with the error
|
||||
.BR EINVAL .
|
||||
.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 fd
|
||||
is not a valid file descriptor.
|
||||
.TP
|
||||
.B ENOENT
|
||||
The program identified by \fIfd\fP and \fIpathname\fP requires the
|
||||
use of an interpreter program (such as a script starting with
|
||||
"#!") but the file descriptor
|
||||
.I fd
|
||||
was opened with the
|
||||
.B O_CLOEXEC
|
||||
flag and so the program file is inaccessible to the launched interpreter.
|
||||
.TP
|
||||
.B EINVAL
|
||||
Invalid flag specified in
|
||||
.IR flags .
|
||||
.TP
|
||||
.B ENOTDIR
|
||||
.I pathname
|
||||
is relative and
|
||||
.I fd
|
||||
is a file descriptor referring to a file other than a directory.
|
||||
.SH VERSIONS
|
||||
.BR execveat ()
|
||||
was added to Linux in kernel 3.???.
|
||||
.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 fexecve (3)
|
||||
Loading…
Reference in New Issue