1funhead(1)                    SAORD Documentation                   funhead(1)
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NAME

6       funhead - display a header in a Funtools file
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SYNOPSIS

9       funhead  [-a] [-s] [-t] [-L] <iname> [oname ename]
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OPTIONS

12         -a    # display all extension headers
13         -s    # display 79 chars instead of 80 before the new-line
14         -t    # prepend data type char to each line of output
15         -L    # output in rdb/starbase list format
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DESCRIPTION

18       funhead displays the FITS header parameters in the specified FITS
19       Extension.
20
21       The first argument to the program specifies the Funtools input file to
22       display.  If "stdin" is specified, data are read from the standard
23       input. Funtools Bracket Notation is used to specify particular FITS
24       extension to process.  Normally, the full 80 characters of each header
25       card is output, followed by a new-line.
26
27       If the -a switch is specified, the header from each FITS extensions in
28       the file is displayed. Note, however, that the -a switch does not work
29       with FITS files input via stdin. We hope to remove this restriction in
30       a future release.
31
32       If the -s switch is specified, only 79 characters are output before the
33       new-line. This helps the display on 80 character terminals.
34
35       If the -t switch is specified, the data type of the parameter is output
36       as a one character prefix, followed by 77 characters of the param.  The
37       parameter data types are defined as: FUN_PAR_UNKNOWN ('u'),
38       FUN_PAR_COMMENT ('c'), FUN_PAR_LOGICAL ('l'), FUN_PAR_INTEGER ('i'),
39       FUN_PAR_STRING ('s'), FUN_PAR_REAL ('r'), FUN_PAR_COMPLEX ('x').
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41       If the -L (rdb table) switch is used, the output will conform to star‐
42       base/rdb data base list format.
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44       For example to display the EVENTS extension (binary table):
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46         [sh] funhead "foo.fits[EVENTS]"
47         XTENSION= 'BINTABLE'            /  FITS 3D BINARY TABLE
48         BITPIX  =                    8  /  Binary data
49         NAXIS   =                    2  /  Table is a matrix
50         NAXIS1  =                   20  /  Width of table in bytes
51         NAXIS2  =                30760  /  Number of entries in table
52         PCOUNT  =                    0  /  Random parameter count
53         GCOUNT  =                    1  /  Group count
54         TFIELDS =                    7  /  Number of fields in each row
55         EXTNAME = 'EVENTS  '            /  Table name
56         EXTVER  =                    1  /  Version number of table
57         TFORM1  = '1I      '            /  Data type for field
58         TTYPE1  = 'X       '            /  Label for field
59         TUNIT1  = '        '            /  Physical units for field
60         TFORM2  = '1I      '            /  Data type for field
61           etc. ...
62         END
63
64       To display the third header:
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66         [sh] funhead "foo.fits[3]"
67         XTENSION= 'BINTABLE'            /  FITS 3D BINARY TABLE
68         BITPIX  =                    8  /  Binary data
69         NAXIS   =                    2  /  Table is a matrix
70         NAXIS1  =                   32  /  Width of table in bytes
71         NAXIS2  =                   40  /  Number of entries in table
72         PCOUNT  =                    0  /  Random parameter count
73         GCOUNT  =                    1  /  Group count
74         TFIELDS =                    7  /  Number of fields in each row
75         EXTNAME = 'TGR     '            /  Table name
76         EXTVER  =                    1  /  Version number of table
77         TFORM1  = '1D      '            /  Data type for field
78           etc. ...
79         END
80
81       To display the primary header (i.e., extension 0):
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83         sh> funhead "coma.fits[0]"
84         SIMPLE  =                    T /STANDARD FITS FORMAT
85         BITPIX  =                   16 /2-BYTE TWOS-COMPL INTEGER
86         NAXIS   =                    2 /NUMBER OF AXES
87         NAXIS1  =                  800 /
88         NAXIS2  =                  800 /
89         DATATYPE= 'INTEGER*2'          /SHORT INTEGER
90         END
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92       The funhead program also can edit (i.e. add, delete, or modify) or dis‐
93       play individual headers parameters. Edit mode is signalled by the pres‐
94       ence of two additional command-line arguments: output file and edit
95       command file, in that order. Edit mode acts as a filter: the output
96       file will contain the entire input FITS file, including other exten‐
97       sions. The edit command file can be "stdin", in which case edit command
98       are read from the standard input.
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100       The edit command file contains parameter comments (having '#' in the
101       first column) and delete and assignment(modify or add) operations.  A
102       delete operation is specified by preceding the parameter name with a
103       minus sign "-".  A display operation (very useful in interactive ses‐
104       sions, i.e., where the edit commands are taken from stdin) is specified
105       by preceding the parameter name with a question mark "?". In either
106       case, a parameter value need not be specified.  An assignment operation
107       is specified in the same two ways that a parameter is specified in a
108       text header (but without the comment character that precedes header
109       params), i.e.:
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111       ·   FITS-style comments have an equal sign "=" between the keyword and
112           value and an optional slash "/" to signify a comment. The strict
113           FITS rules on column positions are not enforced.
114
115       ·   Free-form comments can have an optional colon separator between the
116           keyword and value. In the absence of quote, all tokens after the
117           keyword are part of the value, i.e. no comment is allowed.
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119       For example, the following interactive session checks for the existence
120       of parameters, adds new parameters, modifies them, and modifies and
121       deletes existing parameters:
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123         sh$ ./funhead snr.ev foo.fits -
124         # look for FOO1
125         ? FOO1
126         WARNING: FOO1 not found
127         # add new foo1
128         FOO1 = 100
129         # add foo2
130         FOO2 = 200
131         # reset foo1 to a different value
132         FOO1 -1
133         # delete foo2
134         -FOO2
135         # change existing value
136         EXTVER 2
137         ? XS-SORT
138         XS-SORT = 'EOF     '            /  type of event sort
139         # delete existing value
140         -XS-SORT
141         # exit
142         ^D
143
144       See Column-based Text Files for more information about header parameter
145       format.
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SEE ALSO

148       See funtools(n) for a list of Funtools help pages
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152version 1.4.2                   January 2, 2008                     funhead(1)
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