Commodore Plus 4 - Page 65

BASIC Version 3.5 Commands, Functions, and System Variables 53
Parameters: file number, variable(s)
1. The file number is a logical file number that identifies the file or device and
links it to other commands. The file or device must have been previously accessed
by an OPEN command with the same logical file number.
2. The variable type must match the type of value to be assigned (e.g., if you
are assigning text values, you must use text-string variables). If the' INPUT#
command contains more than one variable, separate the variables with commas.
Example: 10 OPEN 8,8,15 Accesses the disk drive error channel.
20 INPUT#8, U, E$, T, S Gets three numeric and one text-string values
from the channel and assigns them to N, E$,
T, and S.
30 PRI1TT M", E$, T, S Prints the values on the screen.
40 CLOSE 8 Closes the disk channel.
INSTR Abbr. inS
INSTR (master string, substring, start position)
You can find the position of a text string within another text string by using the
INSTR function. INSTR returns a number that represents the character position
in the master string where the sought string begins. If the sought string is not
present, a value of 0 is returned.
The INSTR function has an optional parameter that lets you begin the text-
string search at any character location in the master string. Use this option if you
have found one instance of the sought string and want to search for additional
appearances of the sought string or if you want to begin the search after some
known occurrence of the sought string. This option is the only way to find
additional instances of the sought string.
Parameters: master string, sought string, starting position
1. The master string is the text string being searched. It can be any text string
enclosed in quotes. You can also use a text-string variable or string expression as
this parameter. Only text-string values are allowed.
Note that blanks and punctuation marks are counted as character positions.
2. The sought string is the text for which you are searching the master string.
The sought string can be any text string enclosed in quotes. You can also use a
text-string variable or string expression as this parameter. Only text-string values
are allowed in the INSTR function.
3. The starting position, which is optional, is a number representing the
character position in the master string where you want to begin the search. The
default is the first position in the master string. Once you have found one instance
of the sought string, you can search for another by issuing another INSTR
command using the location of the found string + 1 as the starting position.