/sys$common/syshlp/helplib.hlb PASCAL, Input Output, Seq Access Input, READ *Conan The Librarian (sorry for the slow response - running on an old VAX) |
The READ procedure reads one or more file components into a variable. Syntax: READ( [[file_variable,]] {variable-identifier [[:radix-specifier]]},... [[, ERROR := error-recovery]] ); The 'file_variable' is the name associated with the input file. If you omit the name of the file, the default is INPUT. The 'variable-identifier' is the name of the variable into which a file component will be read; multiple identifiers are separated by commas. The 'radix-specifier' is one of the format values BIN, OCT, or HEX. These values, when used on a variable identifier, will read the variable in binary, octal, or hexadecimal radix respectively. You can use a radix specifier only when reading from a TEXT file. The 'error-recovery' is the action to be taken if an error occurs during execution of the routine. By default, after the first error, the error message is printed and execution is stopped. The file must be in inspection mode before READ is called. The file remains in inspection mode after execution of a READ procedure. By definition, the READ procedure for a nontext file performs an assignment statement, a GET procedure, and an UNLOCK procedure for each variable. The READ procedure reads from the file until it has found a value for each variable in the list. The first value read is assigned to the first variable in the list, the second value read is assigned to the second variable, and so on. The values and the variables must be of assignment-compatible types. Reading stops if an error occurs. For a TEXT file, more than one component (character) can be read into a single variable. For example, many characters can be read into a string or converted into a numeric variable. The READ procedure repeats the assignment, GET, and UNLOCK process until it has read a sequence of characters that represent a legal value for the next variable in the parameter list. The procedure continues to read components from the file until it has assigned a value to each variable in the list. See the "Compaq Pascal Language Reference Manual" for a complete description of the READ procedure.
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