PQUERY(L)           UNIX Programmer's Manual            PQUERY(L)

NAME
     pquery, pquery2 - get the value of a parameter in an IRAF-style
     parameter file, with possible prompting

SYNOPSIS
     pquery paramfile param [ passign...  ]

DESCRIPTION
     pquery gets the value of the param parameter in the speci-
     fied paramfile and outputs it on the standard output.  If
     the parameter is found in the passign list, the value is
     taken from the list. If the parameter is not found in the
     list, a query is generated on stderr for the parameter.  In
     either case, the new value of the parameter is updated in
     the parameter file (except for hidden parameters IF pquery2 
     is used -- see OPTIONS section below).

     Thus,

          example% pquery src region

     will result in the query:

          region (c 512 512 100): c 512 512 50

     The input string will be returned on stdout:

          c 512 512 50

     On the other hand, if a region value is already placed on
     the command line:

          example% pquery src region region="c 512 512

     no query is generated and the value is returned on stdout:

          c 512 512 50

     The pquery program is nearly always used in scripts.  A
     script is run in which the input consists of various parame-
     ter assignments.  One or more pquery's are run within the
     script to retrieve the value of various parameters.  The
     parameter assignments input on the command line are passed
     to each invocation of the pquery program.  If the user has
     input a value for the parameter being retrieved on the com-
     mand line, the user-input value is returned.  Otherwise a
     query is generated on stderr for the parameter. For example,

          if (`pquery scriptpars doit $*` == "yes") then
               echo "doing it ..."
               doit
          else
               echo "not doing it ..."
          endif

     In this example, if the user runs the script by inputting
     the "doit" parameter, its value is returned and no query is
     generated.  Otherwise, the user will be queried for a value
     for that parameter.  In either case, the value is updated
     into the scriptpars parameter file.

     In searching for the parameter file, .par extension will be
     added to the paramfile name, if no extension is specified.
     If the file is not located in the directory specified by the
     paramfile, the directory pointed to by the UPARM environment
     variable will be searched.

OPTIONS
     pquery2 can be used to emulate the behavior of pre-v3.4
     versions of FTOOLS in that the value of hidden parameters
     will NOT be changed as a result of a call to pquery2.

ENVIRONMENT
     The environment variable UPARM specifies the directory in
     which to look for the parameter file, if the pathname of the
     file is not part of the paramfile specification.

SEE ALSO
     pget(l), plist(l), pquery(l), punlearn(l), pset(l)

NOTES
AUTHOR
     The original IRAF parameter interface was developed by the
     IRAF development group at NOAO, led by Doug Tody.
     Eric Mandel and John Roll (SAO) developed the IRAF-
     compatible host interface. Bruce O'Neel developed the current
     version based on XPI.