Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page dasadc_c

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Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       dasadc_c ( DAS, add data, character )

       void dasadc_c ( SpiceInt            handle,
                       SpiceInt            n,
                       SpiceInt            bpos,
                       SpiceInt            epos,
                       SpiceInt            datlen,
                       const void        * data   )

#### Abstract

       Add character data to a DAS file.

#### Required_Reading

       DAS

#### Keywords

       ARRAY
       ASSIGNMENT
       DAS
       FILES

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       handle     I   DAS file handle.
       n          I   Number of characters to add to file.
       bpos,
       epos       I   Begin and end positions of substrings.
       datlen     I   Common length of the character arrays in `data'.
       data       I   Array providing the set of substrings to be added
                      to the character data in the DAS file.

#### Detailed_Input

       handle      is a file handle of a DAS file opened for writing.

       n           is the total number of characters to add to the specified
                   DAS file.

       bpos,
       epos        are the begin and end character positions that define the
                   substrings in each of the elements of the input array.
                   This routine writes the first `n' characters from the
                   specified set of substrings to the specified DAS file.

       data        is a two-dimensional character array, some portion of whose
                   contents are to be added to the specified DAS file.
                   Specifically, the first `n' characters of the substrings

                      data[i][bpos:epos],    i = 0, ...

                   are appended to the character data in the file.

                   `data' must be declared at least as

                      SpiceChar            data   [r][epos+1]

                   with the dimension `r' being at least

                      r = int( ( n + sublen - 1 ) / sublen )

                   and `sublen', the length of each of the substrings in
                   the array to be added to the DAS file, being

                      sublen  =  epos - bpos + 1

                   The order of characters in the input substrings is
                   considered to increase from left to right within each
                   element of `data', and to increase with the indices of the
                   elements of `data'.

       datlen      is the common length of the character arrays in `data'.

#### Detailed_Output

       None.

       See -Particulars for a description of the effect of this routine.

#### Parameters

       None.

#### Exceptions

       1)  If the input file handle is invalid, an error is signaled
           by a routine in the call tree of this routine.

       2)  If `epos' or `bpos' are outside of the range

              [  0,  datlen - 1  ]

           or if epos < bpos, the error SPICE(BADSUBSTRINGBOUNDS) is
           signaled by a routine in the call tree of this routine.

       3)  If the input count `n' is less than 1, no data will be
           added to the specified DAS file.

       4)  If an I/O error occurs during the data addition attempted
           by this routine, the error is signaled by a routine in the
           call tree of this routine.

       5)  If `n' is greater than the number of characters in the
           specified set of input substrings, the results of calling
           this routine are unpredictable. This routine cannot
           detect this error.

       6)  If the `data' input string pointer is null, the error
           SPICE(NULLPOINTER) is signaled.

       7)  If the `data' input string has length less than one character,
           the error SPICE(NODATA) is signaled.

#### Files

       See the description of the argument `handle' in -Detailed_Input.

#### Particulars

       DAS is a low-level format meant to store and transmit data. As
       such, character data in DAS files are not interpreted by SPICELIB
       DAS input or output routines. There are no limits on which
       character values may be placed in the virtual character array of a
       DAS file.

       This routine adds character data to a DAS file by "appending" them
       after any character data already in the file. The sense in which
       the data are "appended" is that the data will occupy a range of
       logical addresses for character data that immediately follow the
       last logical address of a character that is occupied at the time
       this routine is called. The diagram below illustrates this
       addition:

          +-------------------------+
          |    (already in use)     |  Character logical address 1
          +-------------------------+
                      .
                      .
                      .
          +-------------------------+  last character logical address
          |   (already in use)      |  in use before call to dasadc_c
          +-------------------------+
          |  data[0][bpos]          |  First added character
          +-------------------------+
          |  data[0][bpos+1]        |
          +-------------------------+
                       .
                       .
                       .
          +-------------------------+
          |  data[0][epos]          |
          +-------------------------+
          |  data[1][bpos]          |
          +-------------------------+
                       .
                       .
                       .
          +-------------------------+
          |  data[r-1][c]           |  n'th added character---here `r' is
          +-------------------------+
                                          (SpiceInt)( (n+l-1)/l )

                                       where l = epos - bpos + 1, and
                                       `c' is

                                          bpos + ( n - (r-1)*l ) - 1

       The logical organization of the characters in the DAS file is
       independent of the order of addition to the file or physical
       location of any data of integer or double precision type.

       The actual physical write operations that add the input array
       `data' to the indicated DAS file may not take place before this
       routine returns, since the DAS system buffers data that are
       written as well as data that are read. In any case, the data
       will be flushed to the file at the time the file is closed, if
       not earlier. A physical write of all buffered records can be
       forced by calling the CSPICE routine daswbr_c (DAS, write
       buffered records).

       In order to update character logical addresses that already
       contain data, the CSPICE routine dasudc_c (DAS, update data,
       character) should be used.

#### Examples

       The numerical results shown for this example may differ across
       platforms. The results depend on the SPICE kernels used as
       input, the compiler and supporting libraries, and the machine
       specific arithmetic implementation.

       1) The following example demonstrates the capabilities of the
          DAS character data routines. The reader should notice that
          in these interfaces, the character data are treated not as
          strings (or arrays of strings) but as a stream of single
          characters: DAS character data are not limited to
          human-readable text. For example, one can store images or
          DEM data as DAS character data.

          The example shows how to add a variable amount of character
          data to a new DAS file, how to update some of the character
          logical addresses within that file, and how to read that
          data out to a different array.

          Example code begins here.

          /.
             Program dasadc_ex1
          ./
          #include <stdio.h>
          #include <string.h>
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Local parameters.
             ./
             #define FNAME        "dasadc_ex1.das"
             #define TYPE         "TEST"

             /.
             Local variables.
             ./
             SpiceChar            cdatin [3][22];
             SpiceInt             handle;
             SpiceInt             i;

             SpiceChar            cdastr [31];
             SpiceChar            cdatou [10][30] = {
                                               "..............................",
                                               "..............................",
                                               "..............................",
                                               "..............................",
                                               "..............................",
                                               "..............................",
                                               "..............................",
                                               "..............................",
                                               "         1         2         3",
                                               "123456789012345678901234567890" };

             /.
             Open a new DAS file. Use the file name as the internal
             file name, and reserve no records for comments.
             ./
             dasonw_c ( FNAME, TYPE, FNAME, 0, &handle );

             /.
             Set the input data. Note that these data will be
             considered as a binary data stream: DAS character data
             are not limited to human-readable text. For example,
             one can store images or DEM data as DAS character data.
             ./
             strncpy( cdatin[0], "--F-345678901234567890", 22 );
             strncpy( cdatin[1], "--S-345678901234567890", 22 );
             strncpy( cdatin[2], "--T-IRDxxxxxxxxxxxxxxx", 22 );

             /.
             Add the last 20 characters of the first two elements
             of `cdatin', and the 3rd character from the third one.
             ./
             dasadc_c ( handle, 41, 2, 21, 22, cdatin );

             /.
             Update the 10th, 20th and 30th character in the DAS
             file with a vertical bar.
             ./
             for ( i = 1; i < 4; i++ )
             {
                dasudc_c ( handle, i*10, i*10, 0, 0, 1, "|" );
             }

             /.
             Close the file.
             ./
             dascls_c ( handle );

             /.
             Now verify the addition of data by opening the
             file for read access and retrieving the data.
             ./
             dasopr_c ( FNAME, &handle );

             /.
             Read the 41 characters that we stored on the DAS
             file. Update the data on the `cdatou' array, placing
             6 characters on each element, starting from the
             10th position.
             ./
             dasrdc_c ( handle, 1, 41, 9, 14, 30, cdatou );

             /.
             Dump the data to the screen. Note that the last
             three lines should remain unmodified, and that
             only 5 characters will be written on the 7th line.
             ./
             printf( "\n" );
             printf( "Data from \"%s\":\n", FNAME );
             printf( "\n" );

             for ( i = 0; i < 10; i++ )
             {

                /.
                Add null-terminating character to `cdatou[i]' in order to
                print it to the screen.
                ./
                strncpy( cdastr, cdatou[i], 30 );
                cdastr[30] = '\0';

                printf( "%s\n", cdastr );
             }

             /.
             Close the file.
             ./
             dascls_c ( handle );

             return ( 0 );
          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

          Data from "dasadc_ex1.das":

          .........F-3456...............
          .........789|12...............
          .........345678...............
          .........9|S-34...............
          .........56789|...............
          .........123456...............
          .........7890T................
          ..............................
                   1         2         3
          123456789012345678901234567890

          Note that after run completion, a new DAS file exists in the
          output directory.

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

       J. Diaz del Rio     (ODC Space)

#### Version

       -CSPICE Version 1.0.0, 19-MAY-2021 (JDR)

#### Index_Entries

       add character data to a DAS file

#### Link to routine dasadc_c source file dasadc_c.c

    Fri Dec 31 18:41:03 2021