BSD 4_3_Net_2 release

[unix-history] / usr / src / lib / libc / gen / exec.3

diff --git a/usr/src/lib/libc/gen/exec.3 b/usr/src/lib/libc/gen/exec.3
index 5733b65..921df10 100644 (file)
--- a/usr/src/lib/libc/gen/exec.3
+++ b/usr/src/lib/libc/gen/exec.3
@@ -1,186 +1,258 @@
 .\" Copyright (c) 1991 The Regents of the University of California.
 .\" All rights reserved.
 .\"
 .\" Copyright (c) 1991 The Regents of the University of California.
 .\" All rights reserved.
 .\"

-.\" %sccs.include.redist.man%
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"    This product includes software developed by the University of
+.\"    California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.

 .\"
 .\"

-.\"    @(#)exec.3      6.3 (Berkeley) %G%
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.

 .\"
 .\"

-.TH EXEC 3 ""
-.UC 5
-.SH NAME
-execl, execlp, execle, exect, execv, execvp \- execute a file
-.SH SYNOPSIS
-.nf
-.ft B
-extern char **environ;
-.sp
-execl(const char *path, const char *arg, ...);
-execlp(const char *file, const char *arg, ...);
-execle(const char *path, const char *arg, ...,
-.ti +5
-char *const envp[]);
-exect(const char *path, char *const argv[],
-.ti +5
-char *const envp[]);
-execv(const char *path, char *const argv[]);
-execvp(const char *file, char *const argv[]);
-.ft R
-.fi
-.SH DESCRIPTION
-The exec family of functions replaces the current process image with a
+.\"     @(#)exec.3     6.4 (Berkeley) 4/19/91
+.\"
+.Dd April 19, 1991
+.Dt EXEC 3
+.Os
+.Sh NAME
+.Nm execl ,
+.Nm execlp ,
+.Nm execle ,
+.Nm exect ,
+.Nm execv ,
+.Nm execvp
+.Nd execute a file
+.Sh SYNOPSIS
+.Fd #include <unistd.h>
+.Vt extern char **environ;
+.Ft int
+.Fn execl "const char *path" "const char *arg" ...
+.Ft int
+.Fn execlp "const char *file" "const char *arg" ...
+.Ft int
+.Fn execle "const char *path" "const char *arg" ... "char *const envp[]"
+.Ft int
+.Fn exect "const char *path" "char *const argv[]" 
+.Ft int
+.Fn execv "const char *path" "char *const argv[]"
+.Ft int
+.Fn execvp "const char *file" "char *const argv[]"
+.Sh DESCRIPTION
+The
+.Nm exec
+family of functions replaces the current process image with a

 new process image.
 The functions described in this manual page are front-ends for the function
 new process image.
 The functions described in this manual page are front-ends for the function

-.IR execve (2).
+.Xr execve 2 .

 (See the manual page for
 (See the manual page for

-.I execve
+.Xr execve

 for detailed information about the replacement of the current process.)
 for detailed information about the replacement of the current process.)

-.PP
+.Pp

 The initial argument for these functions is the pathname of a file which
 is to be executed.
 The initial argument for these functions is the pathname of a file which
 is to be executed.

-.PP
-The ``const char *arg'' and subsequent ellipses in the
-.IR execl ,
-.IR execlp ,
+.Pp
+The
+.Fa "const char *arg"
+and subsequent ellipses in the
+.Fn execl ,
+.Fn execlp ,

 and
 and

-.I execle
+.Fn execle

 functions can be thought of as
 functions can be thought of as

-.IR arg0 ,
-.IR arg1 ,
+.Em arg0 ,
+.Em arg1 ,

 \&...,
 \&...,

-.IR argn .
+.Em argn .

 Together they describe a list of one or more pointers to null-terminated
 strings that represent the argument list available to the executed program.
 The first argument, by convention, should point to the file name associated
 with the file being executed.
 The list of arguments
 Together they describe a list of one or more pointers to null-terminated
 strings that represent the argument list available to the executed program.
 The first argument, by convention, should point to the file name associated
 with the file being executed.
 The list of arguments

-.B must
-be terminated by a NULL pointer.
-.PP
+.Em must
+be terminated by a
+.Dv NULL
+pointer.
+.Pp

 The
 The

-.IR exect ,
-.IR execv ,
+.Fn exect ,
+.Fn execv ,

 and
 and

-.I execvp
+.Fn execvp

 functions provide an array of pointers to null-terminated strings that
 represent the argument list available to the new program.
 The first argument, by convention, should point to the file name associated
 with the file begin executed.
 The array of pointers
 functions provide an array of pointers to null-terminated strings that
 represent the argument list available to the new program.
 The first argument, by convention, should point to the file name associated
 with the file begin executed.
 The array of pointers

-.B must
-be terminated by a NULL pointer.
-.PP
+.Sy must
+be terminated by a
+.Dv NULL
+pointer.
+.Pp

 The
 The

-.I execle
+.Fn execle

 and
 and

-.I exect
+.Fn exect

 functions also specify the environment of the executed process by following
 functions also specify the environment of the executed process by following

-the NULL pointer that terminates the list of arguments in the parameter list
+the
+.Dv NULL
+pointer that terminates the list of arguments in the parameter list

 or the pointer to the argv array with an additional parameter.
 This additional parameter is an array of pointers to null-terminated strings
 and
 or the pointer to the argv array with an additional parameter.
 This additional parameter is an array of pointers to null-terminated strings
 and

-.B must
-be terminated by a NULL pointer.
+.Em must
+be terminated by a
+.Dv NULL
+pointer.

 The other functions take the environment for the new process image from the
 external variable
 The other functions take the environment for the new process image from the
 external variable

-.I environ
+.Va environ

 in the current process.
 in the current process.

-.PP
+.Pp

 Some of these functions have special semantics.
 Some of these functions have special semantics.

-.PP
+.Pp

 The functions
 The functions

-.I execlp
+.Fn execlp

 and
 and

-.I execvp
+.Fn execvp

 will duplicate the actions of the shell in searching for an executable file
 will duplicate the actions of the shell in searching for an executable file

-if the specified file name does not contain a slash (``/'') character.
-The search path is the path specified in the environment by ``PATH'' variable.
-If this variable isn't specified, the default path ``/bin:/usr/bin:'' is
+if the specified file name does not contain a slash
+.Dq Li /
+character.
+The search path is the path specified in the environment by
+.Dq Ev PATH
+variable.
+If this variable isn't specified, the default path
+.Dq Ev /bin:/usr/bin:
+is

 used.
 In addtion, certain errors are treated specially.
 used.
 In addtion, certain errors are treated specially.

-.PP
+.Pp

 If permission is denied for a file (the attempted
 If permission is denied for a file (the attempted

-.I execve
-returned EACCES), these functions will continue searching the rest of
+.Xr execve
+returned
+.Er EACCES ) ,
+these functions will continue searching the rest of

 the search path.
 the search path.

-If no other file is found, however, they will return with
-.I errno
-set to EACCES.
-.PP
+If no other file is found, however, they will return with the global variable
+.Va errno
+set to
+.Er EACCES .
+.Pp

 If the header of a file isn't recognized (the attempted
 If the header of a file isn't recognized (the attempted

-.I execve
-returned ENOEXEC), these functions will execute the shell with the path of
+.Xr execve
+returned
+.Er ENOEXEC ) ,
+these functions will execute the shell with the path of

 the file as its first argument.
 (If this attempt fails, no further searching is done.)
 the file as its first argument.
 (If this attempt fails, no further searching is done.)

-.PP
+.Pp

 If the file is currently busy (the attempted
 If the file is currently busy (the attempted

-.I execve
-returned ETXTBUSY), these functions will sleep for several seconds,
+.Xr execve
+returned
+.Er ETXTBUSY ) ,
+these functions will sleep for several seconds,

 periodically re-attempting to execute the file.
 periodically re-attempting to execute the file.

-.PP
+.Pp

 The function
 The function

-.I exect
+.Fn exect

 executes a file with the program tracing facilities enabled (see
 executes a file with the program tracing facilities enabled (see

-.IR ptrace (2)).
-.SH "RETURN VALUE"
+.Xr ptrace 2 ) .
+.Sh RETURN VALUES

 If any of the
 If any of the

-.I exec
+.Xr exec

 functions returns, an error will have occurred.
 functions returns, an error will have occurred.

-The return value is -1, and
-.I errno
+The return value is \-1, and the global variable
+.Va errno

 will be set to indicate the error.
 will be set to indicate the error.

-.SH ERRORS
-.IR Execl ,
-.IR execle ,
-.I execlp
+.Sh FILES
+.Bl -tag -width /bin/sh - compact
+.It Pa /bin/sh
+The shell.
+.El
+.Sh ERRORS
+.Fn Execl ,
+.Fn execle ,
+.Fn execlp

 and
 and

-.I execvp
+.Fn execvp

 may fail and set
 may fail and set

-.I errno
+.Va errno

 for any of the errors specified for the library functions
 for any of the errors specified for the library functions

-.IR execve (2)
+.Xr execve 2

 and
 and

-.IR malloc (3).
-.PP
-.I Exect
+.Xr malloc 3 .
+.Pp
+.Fn Exect

 and
 and

-.I execv
+.Fn execv

 may fail and set
 may fail and set

-.I errno
+.Va errno

 for any of the errors specified for the library function
 for any of the errors specified for the library function

-.IR execve (2).
-.SH FILES
-/bin/sh                The shell.
-.SH "SEE ALSO"
-sh(1), execve(2), fork(2),  ptrace(2), environ(7),
-.SH COMPATIBILITY
+.Xr execve 2 .
+.Sh SEE ALSO
+.Xr sh 1 ,
+.Xr execve 2 ,
+.Xr fork 2 ,
+.Xr trace 2 ,
+.Xr environ 7 ,
+.Xr ptrace 2 ,
+.Xr environ 7 ,
+.Sh COMPATIBILITY

 Historically, the default path for the
 Historically, the default path for the

-.I execlp
+.Fn execlp

 and
 and

-.I execvp
-functions was ``:/bin:/usr/bin''.
+.Fn execvp
+functions was
+.Dq Pa :/bin:/usr/bin .

 This was changed to place the current directory last to enhance system
 security.
 This was changed to place the current directory last to enhance system
 security.

-.PP
+.Pp

 The behavior of
 The behavior of

-.I execlp
+.Fn execlp

 and
 and

-.I execvp
+.Fn execvp

 when errors occur while attempting to execute the file is historic
 practice, but has not traditionally been documented and is not specified
 when errors occur while attempting to execute the file is historic
 practice, but has not traditionally been documented and is not specified

-by the POSIX standard.
-.PP
+by the
+.Tn POSIX
+standard.
+.Pp

 Traditionally, the functions
 Traditionally, the functions

-.I execlp
+.Fn execlp
+and
+.Fn execvp
+ignored all errors except for the ones described above and
+.Er ENOMEM

 and
 and

-.I execvp
-ignored all errors except for the ones described above and ENOMEM and
-E2BIG, upon which they returned.
+.Er E2BIG ,
+upon which they returned.

 They now return if any error other than the ones described above occurs.
 They now return if any error other than the ones described above occurs.

-.SH STANDARDS
-.IR Execl ,
-.IR execv ,
-.IR execle ,
-.IR execlp
+.Sh STANDARDS
+.Fn Execl ,
+.Fn execv ,
+.Fn execle ,
+.Fn execlp

 and
 and

-.I execvp
-conform to IEEE Std 1003.1-1988 (``POSIX'').
+.Fn execvp
+conform to
+.St -p1003.1-88 .