Procedure

     COUNTC ( Count characters in a text file )

     INTEGER FUNCTION COUNTC ( UNIT, BLINE, ELINE, LINE )

Abstract

     Count the characters in a group of lines in a text file.

Required_Reading

     None.

Keywords

     CHARACTERS
     FILES

Declarations

     IMPLICIT NONE

     INTEGER               UNIT
     INTEGER               BLINE
     INTEGER               ELINE
     CHARACTER*(*)         LINE

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     UNIT       I   Logical unit connected to text file.
     BLINE      I   Beginning line number.
     ELINE      I   Ending line number.
     LINE      I-O  Workspace.

     The function returns the number of characters in a group of lines
     in a text file.

Detailed_Input

     UNIT     is a logical unit that has been connected to a
              text file by the calling program. Use the routine
              TXTOPR to open the file for read access and get its
              logical unit. A text file is a formatted,
              sequential file that contains only printable
              characters:  ASCII 32-126.

     BLINE,
     ELINE    are line numbers in the text file. BLINE is
              the line where the count will begin, and ELINE
              is the line where the count will end. The
              number of characters in the beginning and ending
              lines are included in the total count.

              By convention, line 1 is the first line of the file.

     LINE     on input, is an arbitrary character string whose
              contents are ignored. LINE is used to read lines
              from the file connected to UNIT; its function
              is to determine the maximum length of the lines
              that can be read from the file. Lines longer
              than the declared length of LINE are truncated
              as they are read.

Detailed_Output

     LINE     on output, is undefined.

     The function returns the number of characters in the group of
     lines in the text file beginning with BLINE and ending with ELINE.
     Trailing blanks on a line are not included in the count.

Parameters

     None.

Exceptions

     1)  If an error occurs while reading from the input file,
         the error SPICE(FILEREADFAILED) is signaled.

     2)  If a non-printing ASCII character is encountered during
         the count, the error SPICE(INVALIDTEXT) is signaled.

     3)  If BLINE is greater than ELINE or if the file does not
         contain both of this lines, the error SPICE(CANNOTFINDGRP)
         is signaled.

Files

     See argument UNIT. COUNTC rewinds the text file connected to
     UNIT and then steps through the file. The next read statement
     after calling COUNTC would return the line after ELINE.

Particulars

     This routine counts characters in a group of lines in a text
     file. Using COUNTC, you can determine in advance how much space
     is required to store those characters.

Examples

     The following code fragment opens an existing text file for
     read access and counts the characters that it contains in
     the first five lines. We'll assume that the longest line
     in the file is 80 characters.

        INTEGER               COUNTC
        INTEGER               UNIT
        INTEGER               N
        CHARACTER*(80)        LINE

        CALL TXTOPR ( 'DATA.TXT', UNIT )

        N = COUNTC ( UNIT, 1, 5, LINE )

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     J.E. McLean        (JPL)
     H.A. Neilan        (JPL)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.2.0, 18-MAR-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.1.0, 17-MAY-1994 (HAN)

        Set the default function value to either 0, 0.0D0, .FALSE.,
        or blank depending on the type of the function.

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 05-APR-1991 (JEM)