IO
var = xred(promptstring, default, min, max)Xred() reads a value from the standard input after printing promptstring
on the console. The value read must be in the range min <= val <= max and
the user will be prompted to enter another number if the value is not in
that range. If the user types the `Return' key, the default value is used
(if it is in the valid range).
IO
getstr(strvar)getstr(strvar, 1)Getstr() reads a string up to and including the next newline from the file
opened with the ropen() command (or the currently executing file or
the standard input) and places it
in its string variable argument. With a second arg equal to 1, getstr reads
a single word starting at the next non-whitespace character up to
but not including the following whitespace (similar to fscan).
IO
index = sred(prompt, defaultchar, charlist)Sred() reads a character typed on the standard input after printing the
first argument followed by the default character. The user is required to
enter one of the characters in the character list (or return if the default
happens to be one of these characters). The function returns the index in
the character list of the character typed. The index of the first character
is 0. The character accepted becomes the next default when this statement
is executed again. This function was contributed by Stewart Jaslove.
i = sred("Shall we?", "y", "ny")
if (i == 0) print "No" else print "yes"
IO
var = fscan()Fscan() reads the next number from the file opened with the ropen()
command. If no file is opened the number is read from the currently
executing file. If no file is being executed the number is read from
the standard input.
A number is scanned as long as it begins with a digit, decimal point, or
sign. There can be more than one number per line but they must be set
apart from each other by spaces or tabs. Strings that can't be scanned
into numbers are skipped.
print fscan(), fscan()
the user types: this is a number 1.3e4 this is not45 this is 25
Then HOC will print: 13000 25
Fscan() and getstr() returns to the HOC
interpreter with a run-time error on EOF.