READLN - read line from text file.

Usage:

readln(f,v);

Where:

f: is a file variable that has been opened for reading using "reset", "openf", or some other means. It must have the type "text". If this argument is omitted, the default input unit "input" is assumed.
v: is a variable whose type is "char", "integer", a subrange of either "char" or "integer", "real", or "packed array [1..N] of char". If this argument is omitted, "readln" simply discards the rest of the line it is reading, up to and including the new-line character on the end.

Description:

The "readln" procedure reads an input line from the text file "f" and stores values obtained from that line in the variable "v". Any text remaining on the line is discarded, up to and including the new-line character on the end.

If "v" has the type "char", a single character is placed in "v" from the "text" file.
If "v" has the type "integer" (or some integer subrange), the "readln" procedure will skip through blanks, tabs, and new-line characters until it finds a digit or a sign (+ or -). It will then gather digits until it finds a character that cannot be part of an integer constant. The integer that is gathered in this way will be assigned to the variable "v". (If the first non-blank character that "readln" finds is NOT valid in an integer, "readln" will issue an error message.)
If "v" has the type "real", the "readln" procedure skips white space characters and gathers a real constant in much the same way that it gathers an integer.
If "v" has the type "packed array [1..N] of char", "readln" will assign input characters to the array elements beginning with number 1. It stops when it fills the array or when it reaches a new-line character in the input, whichever comes first.

A call of the form

readln(f,v1,v2,v3,...,vN);

is equivalent to

read(f,v1);
read(f,v2);
   ...
read(f,vN);
readln(f);

READLN - read line from text file.

Usage:

Where:

Description:

See Also: