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.Dd January 16, 2018
.Dt sysdecode_mask 3
.Os
.Sh NAME
.Nm sysdecode_mask ,
.Nm sysdecode_accessmode ,
.Nm sysdecode_atflags ,
.Nm sysdecode_capfcntlrights ,
.Nm sysdecode_fcntl_fileflags ,
.Nm sysdecode_fileflags ,
.Nm sysdecode_filemode ,
.Nm sysdecode_flock_operation ,
.Nm sysdecode_mlockall_flags ,
.Nm sysdecode_mmap_flags ,
.Nm sysdecode_mmap_prot ,
.Nm sysdecode_mount_flags ,
.Nm sysdecode_msg_flags ,
.Nm sysdecode_msync_flags ,
.Nm sysdecode_open_flags ,
.Nm sysdecode_pipe2_flags ,
.Nm sysdecode_reboot_howto ,
.Nm sysdecode_rfork_flags ,
.Nm sysdecode_semget_flags ,
.Nm sysdecode_sendfile_flags ,
.Nm sysdecode_shmat_flags ,
.Nm sysdecode_sctp_nxt_flags ,
.Nm sysdecode_sctp_rcv_flags ,
.Nm sysdecode_sctp_snd_flags ,
.Nm sysdecode_socket_type ,
.Nm sysdecode_thr_create_flags ,
.Nm sysdecode_umtx_cvwait_flags ,
.Nm sysdecode_umtx_rwlock_flags ,
.Nm sysdecode_vmprot ,
.Nm sysdecode_wait4_options ,
.Nm sysdecode_wait6_options
.Nd print name of various bitmask values
.Sh LIBRARY
.Lb libsysdecode
.Sh SYNOPSIS
.In sys/types.h
.In stdbool.h
.In stdio.h
.In sysdecode.h
.Ft bool
.Fn sysdecode_access_mode "FILE *fp" "int mode" "int *rem"
.Ft bool
.Fn sysdecode_atflags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_cap_fcntlrights "FILE *fp" "uint32_t rights" "uint32_t *rem"
.Ft bool
.Fn sysdecode_fcntl_fileflags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_fileflags "FILE *fp" "fflags_t flags" "fflags_t *rem"
.Ft bool
.Fn sysdecode_filemode "FILE *fp" "int mode" "int *rem"
.Ft bool
.Fn sysdecode_flock_operation "FILE *fp" "int operation" "int *rem"
.Ft bool
.Fn sysdecode_mlockall_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_mmap_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_mmap_prot "FILE *fp" "int prot" "int *rem"
.Ft bool
.Fn sysdecode_mount_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_msg_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_msync_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_open_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_pipe2_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_reboot_howto "FILE *fp" "int howto" "int *rem"
.Ft bool
.Fn sysdecode_rfork_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_sctp_nxt_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_sctp_rcv_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_sctp_snd_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_semget_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_sendfile_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_shmat_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_socket_type "FILE *fp" "int type" "int *rem"
.Ft bool
.Fn sysdecode_thr_create_flags "FILE *fp" "int flags" "int *rem"
.Ft bool
.Fn sysdecode_umtx_cvwait_flags "FILE *fp" "u_long flags" "u_long *rem"
.Ft bool
.Fn sysdecode_umtx_rwlock_flags "FILE *fp" "u_long flags" "u_long *rem"
.Ft bool
.Fn sysdecode_vmprot "FILE *fp" "int type" "int *rem"
.Ft bool
.Fn sysdecode_wait4_options "FILE *fp" "int options" "int *rem"
.Ft bool
.Fn sysdecode_wait6_options "FILE *fp" "int options" "int *rem"
.Sh DESCRIPTION
The
.Nm
functions are used to generate a text description of an integer value
built from a mask of bitfields.
The text description lists the C macros for field values joined by pipe
.Sq |
characters matching the format used in C source code.
Most of the values decoded by these functions are passed as arguments to
system calls,
though some of these values are used internally in the kernel.
.Pp
Each function writes the text description to
.Fa fp .
The second argument should contain the integer value to be decoded.
The
.Fa rem
argument is set to the value of any bits that were not decoded
.Pq bit fields that do not have a corresponding C macro .
.Fa rem
may be set to
.Dv NULL
if the caller does not need this value.
Each function returns
.Dv true
if any bit fields in the value were decoded and
.Dv false
if no bit fields were decoded.
.Pp
Most of these functions decode an argument passed to a system call:
.Bl -column "Fn sysdecode_flock_operation" "Xr cap_fcntls_limit 2"
.It Sy Function Ta Sy System Call Ta Sy Argument
.It Fn sysdecode_access_mode Ta Xr access 2 Ta Fa mode
.It Fn sysdecode_atflags Ta Xr chflagsat 2 , Xr fstatat 2 Ta Fa atflag , Fa flag
.It Fn sysdecode_cap_fcntlrights Ta Xr cap_fcntls_limit 2 Ta Fa fcntlrights
.It Fn sysdecode_fileflags Ta Xr chflags 2 Ta Fa flags
.It Fn sysdecode_filemode Ta Xr chmod 2 , Xr open 2 Ta mode
.It Fn sysdecode_flock_operation Ta Xr flock 2 Ta Fa operation
.It Fn sysdecode_mlockall_flags Ta Xr mlockall 2 Ta Fa flags
.It Fn sysdecode_mmap_flags Ta Xr mmap 2 Ta Fa flags
.It Fn sysdecode_mmap_prot Ta Xr mmap 2 Ta Fa prot
.It Fn sysdecode_mount_flags Ta Xr mount 2 Ta Fa flags
.It Fn sysdecode_msg_flags Ta Xr recv 2 , Xr send 2 Ta Fa flags
.It Fn sysdecode_msync_flags Ta Xr msync 2 Ta Fa flags
.It Fn sysdecode_open_flags Ta Xr open 2 Ta Fa flags
.It Fn sysdecode_pipe2_flags Ta Xr pipe2 Ta Fa flags
.It Fn sysdecode_reboot_howto Ta Xr reboot 2 Ta Fa howto
.It Fn sysdecode_rfork_flags Ta Xr rfork 2 Ta Fa flags
.It Fn sysdecode_semget_flags Ta Xr semget 2 Ta Fa flags
.It Fn sysdecode_sendfile_flags Ta Xr sendfile 2 Ta Fa flags
.It Fn sysdecode_shmat_flags Ta Xr shmat 2 Ta Fa flags
.It Fn sysdecode_socket_type Ta Xr socket 2 Ta Fa type
.It Fn sysdecode_thr_create_flags Ta Xr thr_create 2 Ta Fa flags
.It Fn sysdecode_wait4_options Ta Xr wait4 2 Ta Fa options
.It Fn sysdecode_wait6_options Ta Xr wait6 2 Ta Fa options
.El
.Pp
Other functions decode the values described below:
.Bl -tag -width ".Fn sysdecode_umtx_cvwait_flags"
.It Fn sysdecode_fcntl_fileflags
The file flags used with the
.Dv F_GETFL
and
.Dv F_SETFL
.Xr fcntl 2
commands.
.It Fn sysdecode_sctp_nxt_flags
The
.Fa nxt_flags
member of a
.Vt struct sctp_nxtinfo .
.It Fn sysdecode_sctp_rcv_flags
The
.Fa rcv_flags
member of a
.Vt struct sctp_rcvinfo .
.It Fn sysdecode_sctp_snd_flags
The
.Fa snd_flags
member of a
.Vt struct sctp_sndinfo .
.It Fn sysdecode_umtx_cvwait_flags
The
.Fa val
argument to
.Xr _umtx_op 2
for
.Dv UMTX_OP_CV_WAIT
operations.
.It Fn sysdecode_umtx_rwlock_flags
The
.Fa val
argument to
.Xr _umtx_op 2
for
.Dv UMTX_OP_RW_RDLOCK
operations.
.It Fn sysdecode_vmprot
The memory protection flags stored in
.Vt vm_prot_t
variables.
.El
.Sh RETURN VALUES
The
.Nm
functions return
.Dv true
if any bit fields in the value were decoded and
.Dv false
if no bit fields were decoded.
.Sh SEE ALSO
.Xr sysdecode 3 ,
.Xr sysdecode_enum 3