This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       Since  the  val  exit  status  sets  the  0x80  bit,  shell  applications checking "$?" cannot tell if it
       terminated due to a missing file argument or receipt of a signal.

       Default.

       Default.

       Thefollowingsectionsareinformative.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee  document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any  typographical  or formatting errors that appear in this page are most likely to have been introduced
       during  the  conversion  of  the  source  files  to  man  page  format.  To  report  such   errors,   see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                           VAL(1POSIX)

       The  val  utility  shall determine whether the specified file is an SCCS file meeting the characteristics
       specified by the options.

       The following environment variables shall affect the execution of val:

       LANG      Provide a default value for the internationalization variables that are unset or null. (See the
                 Base Definitions volume of POSIX.1‐2017, Section8.2, InternationalizationVariables  for  the
                 precedence   of   internationalization  variables  used  to  determine  the  values  of  locale
                 categories.)

       LC_ALL    If set to a non-empty string value, override the values of all the  other  internationalization
                 variables.

       LC_CTYPE  Determine  the  locale  for the interpretation of sequences of bytes of text data as characters
                 (for example, single-byte as opposed to multi-byte characters in arguments and input files).

       LC_MESSAGES
                 Determine the locale that should be used to  affect  the  format  and  contents  of  diagnostic
                 messages written to standard error, and informative messages written to standard output.

       NLSPATH   Determine the location of message catalogs for the processing of LC_MESSAGES.

       In a directory with three SCCS files—s.x (of t type  ``text''),  s.y,  and  s.z  (a  corrupted  file)—the
       following command could produce the output shown:

           val - <<EOF
           -y source s.x
           -m y s.y
           s.z
           EOF
           -y source s.x

               s.x: %Y%, -y mismatch
           s.z

               s.z: corrupted SCCS file

       The  8-bit  code  returned  by  val  shall  be  a  disjunction of the possible errors; that is, it can be
       interpreted as a bit string where set bits are interpreted as follows:
       0x80   =   Missing file argument.
       0x40   =   Unknown or duplicate option.
       0x20   =   Corrupted SCCS file.
       0x10   =   Cannot open file or file not SCCS.
       0x08   =   SID is invalid or ambiguous.
       0x04   =   SID does not exist.
       0x02   =   %Y%, -y mismatch.
       0x01   =   %M%, -m mismatch.

       Note that val can process two or more files on a given command line  and  can  process  multiple  command
       lines (when reading the standard input). In these cases an aggregate code shall be returned: a logical OR
       of the codes generated for each command line and file processed.

       None.

       None.

       Any SCCS files processed shall be files of an unspecified format.

       val — validate SCCS files (DEVELOPMENT)

       The following operands shall be supported:

       file      A  pathname  of  an existing SCCS file. If exactly one file operand appears, and it is '-', the
                 standard input shall be read: each line shall be  independently  processed  as  if  it  were  a
                 command  line  argument  list.  (However,  the  line  is not subjected to any of the shell word
                 expansions, such as parameter expansion or quote removal.)

       The val utility shall conform to the Base Definitions  volume  of  POSIX.1‐2017,  Section12.2,  UtilitySyntaxGuidelines, except that the usage of the '-' operand is not strictly as intended by the guidelines
       (that is, reading options and operands from standard input).

       The following options shall be supported:

       -mname   Specify a name, which is compared with the SCCS %M% keyword in file; see get.

       -rSID    Specify  a  SID  (SCCS  Identification  String), an SCCS delta number. A check shall be made to
                 determine whether the SID is ambiguous (for example, -r1 is ambiguous  because  it  physically
                 does  not  exist  but  implies  1.1,  1.2, and so on, which may exist) or invalid (for example,
                 -r1.0 or -r1.1.0 are invalid because neither case can exist as a valid delta number).  If the
                 SID is valid and not ambiguous, a check shall be made to determine whether it actually exists.

       -s        Silence the diagnostic message normally written to  standard  output  for  any  error  that  is
                 detected while processing each named file on a given command line.

       -ytype   Specify a type, which shall be compared with the SCCS %Y% keyword in file; see get.

       None.

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       None.

admin, delta, get, prs

       The  Base  Definitions  volume  of  POSIX.1‐2017, Chapter8, EnvironmentVariables, Section12.2, UtilitySyntaxGuidelines

       Not used.

       The standard input shall be a text file used only when the file operand is specified as '-'.

       The standard output shall consist of informative messages about either:

        1. Each file processed

        2. Each command line read from standard input

       If  the  standard  input is not used, for each file operand yielding a discrepancy, the output line shall
       have the following format:

           "%s: %s\n", <pathname>, <unspecifiedstring>

       If the standard input is used, for each input line yielding a discrepancy,  the  output  shall  have  the
       following format:

           "%s\n\n %s: %s\n", <input>, <pathname>, <unspecifiedstring>

       where <input> is the input line minus its terminating <newline>.

       val -

       val [-s][-m name][-r SID][-y type]file...