Document posix_spawn_file_actions_addclosefrom_np(3)

Reviewed by:    kevans, ngie (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33143

lib/libc/gen/Makefile.inc

@@ -463,6 +463,7 @@ MLINKS+=modf.3 modff.3 \
 MLINKS+=popen.3 pclose.3
 MLINKS+=posix_spawn.3 posix_spawnp.3 \
 	posix_spawn_file_actions_addopen.3 posix_spawn_file_actions_addclose.3 \
+	posix_spawn_file_actions_addopen.3 posix_spawn_file_actions_addclosefrom_np.3 \
 	posix_spawn_file_actions_addopen.3 posix_spawn_file_actions_adddup2.3 \
 	posix_spawn_file_actions_addopen.3 posix_spawn_file_actions_addchdir_np.3 \
 	posix_spawn_file_actions_addopen.3 posix_spawn_file_actions_addfchdir_np.3 \

lib/libc/gen/posix_spawn.3

@@ -422,6 +422,11 @@ in addition to those described by
 This implementation ignores any errors from
 .Fn close ,
 including trying to close a descriptor that is not open.
+The ignore extends to any errors from individual file descriptors
+.Fn close
+executed as part of the
+.Fn closefrom
+action.
 .El
 .Sh SEE ALSO
 .Xr close 2 ,
@@ -434,6 +439,7 @@ including trying to close a descriptor that is not open.
 .Xr setpgid 2 ,
 .Xr vfork 2 ,
 .Xr posix_spawn_file_actions_addclose 3 ,
+.Xr posix_spawn_file_actions_addclosefrom_np 3 ,
 .Xr posix_spawn_file_actions_adddup2 3 ,
 .Xr posix_spawn_file_actions_addopen 3 ,
 .Xr posix_spawn_file_actions_addchdir_np 3 ,

lib/libc/gen/posix_spawn_file_actions_addopen.3

@@ -41,9 +41,10 @@
 .Nm posix_spawn_file_actions_addopen ,
 .Nm posix_spawn_file_actions_adddup2 ,
 .Nm posix_spawn_file_actions_addclose ,
+.Nm posix_spawn_file_actions_addclosefrom_np ,
 .Nm posix_spawn_file_actions_addchdir_np ,
 .Nm posix_spawn_file_actions_addfchdir_np
-.Nd "add open, dup2, close, or chdir/fchdir actions to spawn file actions object"
+.Nd "add open, dup2, close, closefrom, or chdir/fchdir actions to spawn file actions object"
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
@@ -68,6 +69,11 @@
 .Fa "int fildes"
 .Fc
 .Ft int
+.Fo posix_spawn_file_actions_addclosefrom_np
+.Fa "posix_spawn_file_actions_t * file_actions"
+.Fa "int from"
+.Fc
+.Ft int
 .Fo posix_spawn_file_actions_addchdir_np
 .Fa "posix_spawn_file_actions_t *restrict file_actions"
 .Fa "const char *restrict path"
@@ -177,6 +183,14 @@ had been called) when a new process is spawned using this file actions
 object.
 .Pp
 The
+.Fn posix_spawn_file_actions_addclosefrom_np
+function adds a close action to close all file descriptors numerically
+equal or greater then the argument
+.Fa from .
+For each open file descriptor, logically the close action is performed,
+and any possible errors encountered are ignored.
+.Pp
+The
 .Fn posix_spawn_file_actions_addchdir_np
 and
 .Fn posix_spawn_file_actions_addfchdir_np
@@ -238,9 +252,10 @@ is equal to
 A future update of the Standard is expected to require this behavior.
 .Pp
 The
-.Fn posix_spawn_file_actions_addchdir_np
+.Fn posix_spawn_file_actions_addchdir_np ,
+.Fn posix_spawn_file_actions_addfchdir_np ,
 and
-.Fn posix_spawn_file_actions_addfchdir_np
+.Fn posix_spawn_file_actions_addclosefrom_np
 functions are non-standard functions implemented after the similar
 functionality provided by glibc.
 .Sh HISTORY
@@ -252,9 +267,10 @@ and
 functions first appeared in
 .Fx 8.0 .
 The
-.Fn posix_spawn_file_actions_addchdir_np
+.Fn posix_spawn_file_actions_addchdir_np ,
+.Fn posix_spawn_file_actions_addfchdir_np ,
 and
-.Fn posix_spawn_file_actions_addfchdir_np
+.Fn posix_spawn_file_actions_addclosefrom_np
 functions first appeared in
 .Fx 14.0 .
 .Sh AUTHORS

lib/libc/gen/posix_spawn_file_actions_init.3

@@ -83,6 +83,7 @@ Insufficient memory exists to initialize the spawn file actions object.
 .Sh SEE ALSO
 .Xr posix_spawn 3 ,
 .Xr posix_spawn_file_actions_addclose 3 ,
+.Xr posix_spawn_file_actions_addclosefrom_np 3 ,
 .Xr posix_spawn_file_actions_adddup2 3 ,
 .Xr posix_spawn_file_actions_addopen 3 ,
 .Xr posix_spawnp 3