Various pages: Remove unused <sys/types.h>

The manual pages are already inconsistent in which headers need
to be included.  Right now, not all of the types used by a
function have their required header included in the SYNOPSIS.

If we were to add the headers required by all of the types used by
functions, the SYNOPSIS would grow too much.  Not only it would
grow too much, but the information there would be less precise.

Having system_data_types(7) document each type with all the
information about required includes is much more precise, and the
info is centralized so that it's much easier to maintain.

So let's document only the include required for the function
prototype, and also the ones required for the macros needed to
call the function.

<sys/types.h> only defines types, not functions or constants, so
it doesn't belong to man[23] (function) pages at all.

I ignore if some old systems had headers that required you to
include <sys/types.h> *before* them (incomplete headers), but if
so, those implementations would be broken, and those headers
should probably provide some kind of warning.  I hope this is not
the case.

[mtk: Already in 2001, POSIX.1 removed the requirement to
include <sys/types.h> for many APIs, so this patch seems
well past due.]

Acked-by: Zack Weinberg <zackw@panix.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/accept.2

@@ -43,7 +43,6 @@
 accept, accept4 \- accept a connection on a socket
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int accept(int " sockfd ", struct sockaddr *restrict " addr ,
@@ -319,12 +318,6 @@ of file status flags and always explicitly set all required flags on
 the socket returned from
 .BR accept ().
 .SH NOTES
-POSIX.1-2001 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
-.PP
 There may not always be a connection waiting after a
 .B SIGIO
 is delivered or

man2/bind.2

@@ -71,7 +71,6 @@
 bind \- bind a name to a socket
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int bind(int " sockfd ", const struct sockaddr *" addr ,
@@ -243,12 +242,6 @@ first appeared in 4.2BSD).
 .\" .B EISDIR
 .\" UNIX-domain error conditions.
 .SH NOTES
-POSIX.1 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
-.PP
 For background on the
 .I socklen_t
 type, see

man2/connect.2

@@ -69,7 +69,6 @@
 connect \- initiate a connection on a socket
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int connect(int " sockfd ", const struct sockaddr *" addr ,
@@ -276,12 +275,6 @@ first appeared in 4.2BSD).
 .\" It also
 .\" documents many additional error conditions not described here.
 .SH NOTES
-POSIX.1 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
-.PP
 For background on the
 .I socklen_t
 type, see

man2/fork.2

@@ -41,7 +41,6 @@
 fork \- create a child process
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .B pid_t fork(void);

man2/get_robust_list.2

@@ -33,7 +33,6 @@ get_robust_list, set_robust_list \- get/set list of robust futexes
 .SH SYNOPSIS
 .nf
 .B #include <linux/futex.h>
-.B #include <sys/types.h>
 .B #include <syscall.h>
 .PP
 .BI "long get_robust_list(int " pid ", struct robust_list_head **" head_ptr ,

man2/getgid.2

@@ -28,7 +28,6 @@ getgid, getegid \- get group identity
 .SH SYNOPSIS
 .nf
 .B #include <unistd.h>
-.B #include <sys/types.h>
 .PP
 .B gid_t getgid(void);
 .B gid_t getegid(void);

man2/getgroups.2

@@ -34,7 +34,6 @@
 getgroups, setgroups \- get/set list of supplementary group IDs
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int getgroups(int " size ", gid_t " list []);

man2/getpid.2

@@ -27,7 +27,6 @@
 getpid, getppid \- get process identification
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .B pid_t getpid(void);

man2/getsid.2

@@ -29,7 +29,6 @@
 getsid \- get session ID
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "pid_t getsid(pid_t" " pid" );

man2/getsockopt.2

@@ -46,7 +46,6 @@
 getsockopt, setsockopt \- get and set options on sockets
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int getsockopt(int " sockfd ", int " level ", int " optname ,
@@ -179,12 +178,6 @@ SVr4, 4.4BSD (these system calls first appeared in 4.2BSD).
 .\" .BR SO_SNDLOWAT ", " SO_RCVLOWAT ", " SO_SNDTIMEO ", " SO_RCVTIMEO
 .\" options
 .SH NOTES
-POSIX.1 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
-.PP
 For background on the
 .I socklen_t
 type, see

man2/gettid.2

@@ -30,7 +30,6 @@ gettid \- get thread identification
 .nf
 .B #define _GNU_SOURCE
 .B #include <unistd.h>
-.B #include <sys/types.h>
 .PP
 .B pid_t gettid(void);
 .fi

man2/getuid.2

@@ -29,7 +29,6 @@ getuid, geteuid \- get user identity
 .SH SYNOPSIS
 .nf
 .B #include <unistd.h>
-.B #include <sys/types.h>
 .PP
 .B uid_t getuid(void);
 .B uid_t geteuid(void);

man2/getxattr.2

@@ -28,7 +28,6 @@ getxattr, lgetxattr, fgetxattr \- retrieve an extended attribute value
 .SH SYNOPSIS
 .fam C
 .nf
-.B #include <sys/types.h>
 .B #include <sys/xattr.h>
 .PP
 .BI "ssize_t getxattr(const char *" path ", const char *" name ,

man2/keyctl.2

@@ -30,7 +30,6 @@
 keyctl \- manipulate the kernel's key management facility
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <keyutils.h>
 .PP
 .BI "long keyctl(int " operation ", ...);"

man2/kill.2

@@ -46,7 +46,6 @@
 kill \- send signal to a process
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <signal.h>
 .PP
 .BI "int kill(pid_t " pid ", int " sig );

man2/listen.2

@@ -47,7 +47,6 @@
 listen \- listen for connections on a socket
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int listen(int " sockfd ", int " backlog );
@@ -140,12 +139,6 @@ Connections are accepted with
 .BR accept (2).
 .RE
 .PP
-POSIX.1 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
-.PP
 The behavior of the
 .I backlog
 argument on TCP sockets changed with Linux 2.2.

man2/listxattr.2

@@ -29,7 +29,6 @@ listxattr, llistxattr, flistxattr \- list extended attribute names
 .SH SYNOPSIS
 .fam C
 .nf
-.B #include <sys/types.h>
 .B #include <sys/xattr.h>
 .PP
 .BI "ssize_t listxattr(const char *" path ", char *" list \

man2/llseek.2

@@ -31,7 +31,6 @@
 _llseek \- reposition read/write file offset
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int _llseek(unsigned int " fd ", unsigned long " offset_high ,

man2/lseek.2

@@ -48,7 +48,6 @@
 lseek \- reposition read/write file offset
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "off_t lseek(int " fd ", off_t " offset ", int " whence );

man2/mkdir.2

@@ -14,7 +14,6 @@ mkdir, mkdirat \- create a directory
 .SH SYNOPSIS
 .nf
 .B #include <sys/stat.h>
-.B #include <sys/types.h>
 .\" .B #include <unistd.h>
 .PP
 .BI "int mkdir(const char *" pathname ", mode_t " mode );

man2/mknod.2

@@ -17,7 +17,6 @@
 mknod, mknodat \- create a special or ordinary file
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/stat.h>
 .B #include <fcntl.h>
 .B #include <unistd.h>

man2/modify_ldt.2

@@ -27,8 +27,6 @@
 modify_ldt \- get or set a per-process LDT entry
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
-.PP
 .BI "int modify_ldt(int " func ", void *" ptr ", unsigned long " bytecount );
 .fi
 .PP

man2/mq_getsetattr.2

@@ -27,7 +27,6 @@
 mq_getsetattr \- get/set message queue attributes
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <mqueue.h>
 .PP
 .BI "int mq_getsetattr(mqd_t " mqdes ", const struct mq_attr *" newattr ,

man2/msgctl.2

@@ -40,7 +40,6 @@
 msgctl \- System V message control operations
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/ipc.h>
 .B #include <sys/msg.h>
 .PP
@@ -407,17 +406,15 @@ POSIX.1-2001, POSIX.1-2008, SVr4.
 .\" SVID does not document the EIDRM error condition.
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
+.\" the inclusion of this header file.
 .PP
 The
 .BR IPC_INFO ,

man2/msgget.2

@@ -37,7 +37,6 @@
 msgget \- get a System V message queue identifier
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/ipc.h>
 .B #include <sys/msg.h>
 .PP
@@ -190,17 +189,15 @@ would be exceeded.
 POSIX.1-2001, POSIX.1-2008, SVr4.
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
+.\" the inclusion of this header file.
 .PP
 .B IPC_PRIVATE
 isn't a flag field but a

man2/msgop.2

@@ -42,7 +42,6 @@
 msgrcv, msgsnd \- System V message queue operations
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/ipc.h>
 .B #include <sys/msg.h>
 .PP
@@ -482,17 +481,15 @@ their definitions can be obtained by defining the
 feature test macro.
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
+.\" the inclusion of this header file.
 .PP
 The
 .I msgp

man2/open.2

@@ -53,7 +53,6 @@
 open, openat, creat \- open and possibly create a file
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/stat.h>
 .B #include <fcntl.h>
 .PP

man2/open_by_handle_at.2

@@ -29,7 +29,6 @@ for a pathname and open file via a handle
 .SH SYNOPSIS
 .nf
 .BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
-.B #include <sys/types.h>
 .B #include <sys/stat.h>
 .B #include <fcntl.h>
 .PP

man2/openat2.2

@@ -26,7 +26,6 @@
 openat2 \- open and possibly create a file (extended)
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/stat.h>
 .B #include <fcntl.h>
 .B #include <linux/openat2.h>

man2/pidfd_open.2

@@ -27,8 +27,6 @@
 pidfd_open \- obtain a file descriptor that refers to a process
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
-.PP
 .BI "int pidfd_open(pid_t " pid ", unsigned int " flags );
 .fi
 .PP

man2/recv.2

@@ -43,7 +43,6 @@
 recv, recvfrom, recvmsg \- receive a message from a socket
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/socket.h>
 .PP
 .BI "ssize_t recv(int " sockfd ", void *" buf ", size_t " len ", int " flags );

man2/removexattr.2

@@ -28,7 +28,6 @@ removexattr, lremovexattr, fremovexattr \- remove an extended attribute
 .SH SYNOPSIS
 .fam C
 .nf
-.B #include <sys/types.h>
 .B #include <sys/xattr.h>
 .PP
 .BI "int removexattr(const char\ *" path ", const char\ *" name );

man2/request_key.2

@@ -14,7 +14,6 @@
 request_key \- request a key from the kernel's key management facility
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <keyutils.h>
 .PP
 .BI "key_serial_t request_key(const char *" type ", const char *" description ,

man2/semctl.2

@@ -44,7 +44,6 @@
 semctl \- System V semaphore control operations
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/ipc.h>
 .B #include <sys/sem.h>
 .PP
@@ -538,15 +537,13 @@ but, since Linux 2.4, the field has the type
 .IR "unsigned\ long" .
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
 .\" the inclusion of these header files.
 .PP

man2/semget.2

@@ -39,7 +39,6 @@
 semget \- get a System V semaphore set identifier
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/ipc.h>
 .B #include <sys/sem.h>
 .fi
@@ -221,17 +220,15 @@ SVr4, POSIX.1-2001.
 .\" ERANGE, EFAULT.
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
+.\" the inclusion of this header file.
 .PP
 .B IPC_PRIVATE
 isn't a flag field but a

man2/semop.2

@@ -37,7 +37,6 @@
 semop, semtimedop \- System V semaphore operations
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/ipc.h>
 .B #include <sys/sem.h>
 .PP
@@ -385,17 +384,15 @@ POSIX.1-2001, POSIX.1-2008, SVr4.
 .\" SVr4 documents additional error conditions EINVAL, EFBIG, ENOSPC.
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
+.\" the inclusion of this header file.
 .PP
 The
 .I sem_undo

man2/send.2

@@ -42,7 +42,6 @@
 send, sendto, sendmsg \- send a message on a socket
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/socket.h>
 .PP
 .BI "ssize_t send(int " sockfd ", const void *" buf ", size_t " len \

man2/seteuid.2

@@ -31,7 +31,6 @@
 seteuid, setegid \- set effective user or group ID
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int seteuid(uid_t " euid );

man2/setgid.2

@@ -32,7 +32,6 @@
 setgid \- set group identity
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int setgid(gid_t " gid );

man2/setpgid.2

@@ -50,7 +50,6 @@
 setpgid, getpgid, setpgrp, getpgrp \- set/get process group
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int setpgid(pid_t " pid ", pid_t " pgid );

man2/setreuid.2

@@ -48,7 +48,6 @@
 setreuid, setregid \- set real and/or effective user or group ID
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int setreuid(uid_t " ruid ", uid_t " euid );

man2/setsid.2

@@ -34,7 +34,6 @@ setsid \- creates a session and sets the process group ID
 .SH SYNOPSIS
 .nf
 .ad l
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .B pid_t setsid(void);

man2/setuid.2

@@ -33,7 +33,6 @@
 setuid \- set user identity
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .BI "int setuid(uid_t " uid );

man2/setxattr.2

@@ -28,7 +28,6 @@ setxattr, lsetxattr, fsetxattr \- set an extended attribute value
 .SH SYNOPSIS
 .fam C
 .nf
-.B #include <sys/types.h>
 .B #include <sys/xattr.h>
 .PP
 .BI "int setxattr(const char\ *" path ", const char\ *" name ,

man2/shmctl.2

@@ -467,17 +467,15 @@ POSIX.1-2001, POSIX.1-2008, SVr4.
 .\" an EIDRM error condition.
 .SH NOTES
 The inclusion of
-.I <sys/types.h>
-and
 .I <sys/ipc.h>
 isn't required on Linux or by any version of POSIX.
 However,
-some old implementations required the inclusion of these header files,
+some old implementations required the inclusion of this header file,
-and the SVID also documented their inclusion.
+and the SVID also documented its inclusion.
 Applications intended to be portable to such old systems may need
-to include these header files.
+to include this header file.
 .\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
+.\" the inclusion of this header file.
 .PP
 The
 .BR IPC_INFO ,

man2/socket.2

@@ -44,7 +44,6 @@
 socket \- create an endpoint for communication
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int socket(int " domain ", int " type ", int " protocol );
@@ -467,12 +466,6 @@ It is generally portable to/from
 non-BSD systems supporting clones of the BSD socket layer (including
 System\ V variants).
 .SH NOTES
-POSIX.1 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
-.PP
 The manifest constants used under 4.x BSD for protocol families
 are
 .BR PF_UNIX ,

man2/socketpair.2

@@ -44,7 +44,6 @@
 socketpair \- create a pair of connected sockets
 .SH SYNOPSIS
 .nf
-.BR "#include <sys/types.h>" "          /* See NOTES */"
 .B #include <sys/socket.h>
 .PP
 .BI "int socketpair(int " domain ", int " type ", int " protocol \
@@ -130,12 +129,6 @@ flags in the
 .I type
 argument, as described in
 .BR socket (2).
-.PP
-POSIX.1 does not require the inclusion of
-.IR <sys/types.h> ,
-and this header file is not required on Linux.
-However, some historical (BSD) implementations required this header
-file, and portable applications are probably wise to include it.
 .SH SEE ALSO
 .BR pipe (2),
 .BR read (2),

man2/statx.2

@@ -32,7 +32,6 @@
 statx \- get file status (extended)
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/stat.h>
 .B #include <unistd.h>
 .BR "#include <fcntl.h>           " "/* Definition of AT_* constants */"

man2/vfork.2

@@ -31,7 +31,6 @@
 vfork \- create a child process and block parent
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <unistd.h>
 .PP
 .B pid_t vfork(void);