system_data_types.7: Add 'id_t'

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

diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index 46a3104048c256477a70d8adf713626f282c4371..b026541b068458ca3da0e9a029c54f17afcd2d13 100644 (file)
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -146,6 +146,28 @@ See also:
 .BR getresgid (2),
 .BR getgrnam (2),
 .BR credentials (7)
+.\"------------------------------------- id_t -------------------------/
+.TP
+.I id_t
+.IP
+Include:
+.IR <sys/types.h> ;
+or
+.IR <sys/resource.h> .
+.IP
+A type used to hold a general identifier.
+According to POSIX,
+this shall be an integer type that can be used to contain a
+.IR pid_ t ,
+.IR uid_ t ,
+or
+.IR gid_ t .
+.IP
+Conforming to: POSIX.1-2001 and later.
+.IP
+See also:
+.BR getpriority (2),
+.BR waitid (2)
 .\"------------------------------------- pid_t ------------------------/
 .TP
 .I pid_t