READ - read input from file.

var
    f : file of TYPE;
    v : TYPE;
  ...
read(f,v);

f: is a file variable that has been opened for reading using "reset", "openf", or some other means. If this argument is omitted, the default input unit "input" is assumed.
v: is a variable whose type matches the type of the elements in the file "f".

The "read" procedure reads a single element from the file "f" and stores the value of that element in the variable "v". It is equivalent to

v := f^;
get(f);

A call of the form

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

is equivalent to

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

Special processing is available if "f" is declared with the type "text". In this case, the variable "v" may have several different types.

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 "read" 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 "read" finds is NOT valid in an integer, "read" will issue an error message.)
If "v" has the type "real", the "read" 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", "read" 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.