M400: Portable Conversion Between Type CHARACTER and Type INTEGER

Author(s): H. Renshall	Library: KERNLIB
Submitter: M. Metcalf	Submitted: 27.11.1984
Language: Fortran	Revised: 12.03.1985

CHTOI converts between a CHARACTER*1 value in a 95-character set and INTEGER values in the range 32-126 via a look-up table.

Structure:

SUBROUTINE subprogram
User Entry Names: CHTOI, ITOCH

Usage:

    CALL CHTOI(CHAR,INTGR,*label)

CHAR

(CHARACTER*1) Variable or constant (may be a substring of a longer string) containing on input the character for which the integer equivalent is required.

INTGR

(INTEGER) Variable which will contain on output the integer equivalent from a look-up table of the input character argument. A zero will be returned if the character was not found in the table.

label

(INTEGER) Label of an executable statement within the calling program to which control will be transferred should the input character not be found in the table.

    CALL ITOCH(INTGR,CHAR,*label)

CHAR

(CHARACTER*1) variable which will contain on output the character equivalent from a look-up table of the input integer argument. A question mark will be returned if the integer is outside the range inclusive.

INTGR

(INTEGER) variable or constant containing on input an integer in the range for which the character equivalent is required.

label

(INTEGER) Label of an executable statement in the calling program to which control will be transferred should the input integer be outside the range .

Method:

A look-up table containing 95 entries is mapped consecutively into integers . The table is as follows:

 32- 47:   ! " # $ % & ' ( ) * + , - . / (32 is a blank)
 48- 57: 0 ... 9
 58- 64: : ; < = > ? @
 65- 90: A ... Z
 91- 96: [ \ ] ^ _ `
 97-122: a ... z
123-126: { | } ~

Restrictions:

This routine is typed in Fortran on a system which includes all the above characters. Systems with fewer characters available usually make some local translation when they read the source for example on CDC NOS/BE the lower case letters are translated to upper case. Exact reproducibility of other than the subset of characters is not guaranteed.

Notes:

These integer values are the same as for the 8-bit ASCII set.