WRITE statement
Standard: (F77) F90 F95 F2003 F2008 Example program
＜Syntax＞
WRITE ( ci-spec [ , ci-spec ]... ) [ output-list ]
output-list ::= output-item [ , output-item ]...
output-item ::= expr | ( output-list , do-spec )
do-spec ::= variable-name = m1 , m2 [ , m3 ]
m1 ::= initial-scalar-integer-expr
m2 ::= final-scalar-integer-expr
m3 ::= step-scalar-integer-expr
The possible ci-specs are listed in the table below, together with their meaning.
The UNIT= ci-spec is required; the UNIT= keyword and equals sign may be omitted if it is the first ci-spec. If UNIT= was omitted, the FMT= keyword and equals sign may omitted if it is the second ci-spec, or the NML= keyword and equals sign may be omitted if it is the second ci-spec.
＜Semantics＞
The WRITE statement writes one or more records, or partial records, to the specified unit. Each ci-spec is listed in the table below.
If unit is *, the output is to the standard output unit (usually the screen); if it is a character variable, the output is to that variable; if it is an integer expr, the output is to the external unit with that number, which must be non-negative.
If format is present, the WRITE is a formatted WRITE; if format is *, list-directed formatting is used; if format is a label, that FORMAT statement is used; if format is a character expression, that expression is interpreted as an explicit format. The WRITE is also a formatted WRITE if Namelist is present, in which case namelist formatting is used.
The form “( output-list , do-spec )” evaluates the output-list for each value of variable-name implied by the do-spec; for further details see the DO statement. Implied DO loops may be nested.
| Specifier | Argument | Meaning | Values |
| [ UNIT = ] | unit | Unit to write to | |
| [ FMT = ] | format | Formatting | |
| ADVANCE= | Character | Advancing input? | 'YES', 'NO' |
| ASYNCHRONOUS= | Character | Async i/o? | 'YES', 'NO' |
| DECIMAL= | Character | Decimal edit mode | 'COMMA', 'POINT' |
| DELIM= | Character | Delimiter mode | 'NONE', 'QUOTE', 'APOSTROPHE' |
| ERR= | Label | Branch on error | |
| ID= | Integer | Pending i/o identifier | |
| IOMSG= | Character | Error message | |
| IOSTAT= | Integer | I/O status | |
| [ NML= ] | Namelist | Namelist formatting | |
| POS= | Integer | File storage position | Positive |
| REC= | Integer | Record number | Positive |
| ROUND= | Character | Rounding mode | 'COMPATIBLE', 'DOWN', 'NEAREST', 'PROCESSOR_DEFINED', 'UP', 'ZERO' |
| SIGN= | Character | Sign edit mode | 'PLUS', 'SUPPRESS', 'PROCESSOR_DEFINED' |
The ADVANCE= specifier is only allowed for external files. If the [ NML= ] specifier appears, no format is allowed. The REC= specifier is only allowed for a direct access file.
In Fortran 2003, the DECIMAL=, DELIM=, ROUND= and SIGN= specifiers control the initial edit modes for that WRITE; if omitted, the default is taken from the OPEN. The IOMSG= specifier sets its variable to an error message if an error occurs. The POS= specifier is only allowed for stream files, and specifies the file storage position at which to start writing. The ID= specifier is only allowed in conjunction with ASYNCHRONOUS='YES', and sets the variable to an identifier for that asynchronous input/output (this variable can then be used in an ID= specifier in INQUIRE or WAIT).
＜Related＞
ADVANCE= specifier, ASYNCHRONOUS= specifier, BACKSPACE statement, CLOSE statement, DECIMAL= specifier, DO statement, ENDFILE statement, ERR= specifier, FORMAT statement, ID= specifier, INQUIRE statement, IOMSG= specifier, IOSTAT= specifier, NAMELIST statement, NML= specifier, OPEN statement, PRINT statement, READ statement, REWIND statement, ROUND= specifier, SIGN= specifier