Signed-off-by: David Drysdale <drysdale@xxxxxxxxxx> --- man2/execveat.2 | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 153 insertions(+) create mode 100644 man2/execveat.2 diff --git a/man2/execveat.2 b/man2/execveat.2 new file mode 100644 index 000000000000..937d79e4c4f0 --- /dev/null +++ b/man2/execveat.2 @@ -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 +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date.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) -- 2.1.0.rc2.206.gedb03e5 -- 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
