execveat.2: Light edits to new page

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/execveat.2

@@ -22,24 +22,26 @@
 .\" the source, must acknowledge the copyright and authors of this work.
 .\" %%%LICENSE_END
 .\"
-.TH EXECVEAT 2 2014-04-02 "Linux" "Linux Programmer's Manual"
+.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 " fd ", const char *" pathname ","
+.BI "int execveat(int " dirfd ", const char *" pathname ","
 .br
-.BI "             char *const " argv "[],  char *const " envp "[],"
+.BI "             char *const " argv "[], char *const " envp "[],"
 .br
-.BI "             int " flags);
+.BI "             int " flags );
 .SH DESCRIPTION
+.\" commit 51f39a1f0cea1cacf8c787f652f26dfee9611874
 The
 .BR execveat ()
-system call executes the program pointed to by the combination of \fIfd\fP and \fIpathname\fP.
+system call executes the program referred to by the combination of
-The
+.I dirfd
-.BR execveat ()
+and
-system call operates in exactly the same way as
+.IR pathname .
+It operates in exactly the same way as
 .BR execve (2),
 except for the differences described in this manual page.
 
@@ -47,7 +49,7 @@ 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
+.I dirfd
 (rather than relative to the current working directory of
 the calling process, as is done by
 .BR execve (2)
@@ -56,7 +58,7 @@ for a relative pathname).
 If
 .I pathname
 is relative and
-.I fd
+.I dirfd
 is the special value
 .BR AT_FDCWD ,
 then
@@ -68,7 +70,7 @@ directory of the calling process (like
 If
 .I pathname
 is absolute, then
-.I fd
+.I dirfd
 is ignored.
 
 If
@@ -76,17 +78,20 @@ If
 is an empty string and the
 .BR AT_EMPTY_PATH
 flag is specified, then the file descriptor
-.I fd
+.I dirfd
-specifies the file to be executed.
+specifies the file to be executed (i.e.,
+.IR dirfd
+refers to an executable file, rather than a directory).
 
+The
 .I flags
-can either be 0, or include the following 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 fd
+.IR dirfd
 (which may have been obtained using the
 .BR open (2)
 .B O_PATH
@@ -94,7 +99,7 @@ flag).
 .TP
 .B AT_SYMLINK_NOFOLLOW
 If the file identified by
-.I fd
+.I dirfd
 and a non-NULL
 .I pathname
 is a symbolic link, then the call fails with the error
@@ -102,7 +107,8 @@ is a symbolic link, then the call fails with the error
 .SH "RETURN VALUE"
 On success,
 .BR execveat ()
-does not return. On error \-1 is returned, and
+does not return.
+On error, \-1 is returned, and
 .I errno
 is set appropriately.
 .SH ERRORS
@@ -114,30 +120,34 @@ The following additional errors can occur for
 .BR execveat ():
 .TP
 .B EBADF
-.I fd
+.I dirfd
 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 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 fd
+.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.???.
+was added to Linux in kernel 3.19.
 .SH NOTES
 In addition to the reasons explained in
 .BR openat (2),
@@ -150,4 +160,5 @@ to be implemented on systems that do not have the
 filesystem mounted.
 .SH SEE ALSO
 .BR execve (2),
+.BR openat (2),
 .BR fexecve (3)