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# LogiView

## Command 'readln'

| This command is used to read a file line-by-line. The contents of a line is assigned to a variable of the forwarded variable list. It must be ensured that the variable types correspond to the contents of the appropriate line.
| This command must not be called with a conditional instruction.
| ### Syntax:
| readln({INT_VAR},{VAR_LIST})
| ### I/O parameters:
| {INT_VAR} | Integer variable with file ID number (is assigned when opening the file).
| {VAR_LIST} | List of variables that are assigned values. The following values are valid for logic variables:
TRUE | FALSE
'TRUE' | 'FALSE'
'Y' | 'N'
'J' | 'n'
'O' |
'y' |
'j' |
'o' |
| ### Return value:
| - |
| ### Return code:
| 0 | No errors during command execution.
| ### Example:
| Declaration of Variables
     10 C Generating file "test.file"
     20   DOCU_LOGIC_1=FALSE
     30   DOCU_INT_1 = open("\tmp\test.file","w")
     40   writeln(DOCU_INT_1,"Line 1")
     50   writeln(DOCU_INT_1,5)
     60   writeln(DOCU_INT_1,"Line 2")
     70   close(DOCU_INT_1)
     80 C Reading data from file "test.file"
     90   DOCU_INT_1 = open("\tmp\test.file","r")
    100   DOCU_LOGIC_1 = eof (DOCU_INT_1)
    110   while ( DOCU_LOGIC_1 != TRUE)
    120     readln(DOCU_INT_1,DOCU_STRING_1)
    130     readln(DOCU_INT_1,DOCU_INT_2)
    140     put(DOCU_STRING_1)
    150     put(DOCU_INT_2)
    160     DOCU_LOGIC_1 = eof (DOCU_INT_1)
    170   done
    180   close(DOCU_INT_1)
    190 C Deleting file "test.file"
    200   delete("\tmp\test.file")
| Result:
test.file:
    Zeile 1
    5
    Zeile 2
| In the last line the value "5" is returned again because the end of file is reached before all variables in the list are assigned a value. In this case the variable maintains its value.
| Functions and commands: File Interface