6.7.2 Low-Level Table Access Subroutines

The following subroutines provide low-level access to the data in ASCII or binary tables and are mainly useful as an efficient way to copy all or part of a table from one location to another. These routines simply read or write the specified number of consecutive bytes in an ASCII or binary table, without regard for column boundaries or the row length in the table. The first two subroutines read or write consecutive bytes in a table to or from a character string variable, while the last two subroutines read or write consecutive bytes to or from a variable declared as a numeric data type (e.g., INTEGER, INTEGER*2, REAL, DOUBLE PRECISION). These routines do not perform any machine dependent data conversion or byte swapping, except that conversion to/from ASCII format is performed by the FTGTBS and FTPTBS routines on machines which do not use ASCII character codes in the internal data representations (e.g., on IBM mainframe computers).

1

Read a consecutive string of characters from an ASCII table into a character variable (spanning columns and multiple rows if necessary) This routine should not be used with binary tables because of complications related to passing string variables between C and Fortran.

        FTGTBS(unit,frow,startchar,nchars, > string,status)

2

Write a consecutive string of characters to an ASCII table from a character variable (spanning columns and multiple rows if necessary) This routine should not be used with binary tables because of complications related to passing string variables between C and Fortran.

        FTPTBS(unit,frow,startchar,nchars,string, > status)

3

Read a consecutive array of bytes from an ASCII or binary table into a numeric variable (spanning columns and multiple rows if necessary). The array parameter may be declared as any numerical datatype as long as the array is at least 'nchars' bytes long, e.g., if nchars = 17, then declare the array as INTEGER*4 ARRAY(5).

        FTGTBB(unit,frow,startchar,nchars, > array,status)

4

Write a consecutive array of bytes to an ASCII or binary table from a numeric variable (spanning columns and multiple rows if necessary) The array parameter may be declared as any numerical datatype as long as the array is at least 'nchars' bytes long, e.g., if nchars = 17, then declare the array as INTEGER*4 ARRAY(5).

        FTPTBB(unit,frow,startchar,nchars,array, > status)