FileReadLine() syntax question

[millisys]

Hi, I am using the FileReadLine() function to proceed through the dates of a calendar and then using the FileReadLine function to view tomorrow's schedule simultaneously.

The code shows tomorrow's schedule perfectly but then causes the FileReadLine() function to skip a line.

For example, in the code and test.txt file below it will skip from 11/01/2012 to 11/03/2012

Would someone be so kind as to show me how should the code be written differently so that it works as intended without skipping a line?

11/01/2012,mary
11/02/2012,sue
11/03/2012,jane
11/04/2012,bob

$file = FileOpen("test.txt", 0)
$linenumber = 0
While 1
$line = FileReadLine($file)
If @error = -1 Then ExitLoop
$linenumber += 1
MsgBox(0, "", $line & @CRLF & FileReadLine($file,$linenumber+1))
Wend
FileClose($file)

Edited May 8, 2013 by millisys

[Nessie]

Try _FileReadToArray

#include <File.au3>

$file = "test.txt"

Local $aRecords
If Not _FileReadToArray($file, $aRecords) Then
    MsgBox(4096, "Error", " Error reading log to Array     error:" & @error)
    Exit
EndIf

For $x = 1 To $aRecords[0]
    MsgBox(0, 'Record:' & $x, $aRecords[$x])
Next

Hi!

[BrewManNH]

To the OP, FileReadLine without a line number will read the next line of a file. If you use FileReadLine($sometextfile, 11) and then use FileReadLine($sometextfile) it's going to read line 12 because the last line it read was 11. Using FileReadLine with a line number will be very slow on large text files, so is usually avoided.

[Werty]

Your code working

$file = FileOpen("test.txt", 0)
$linenumber = 0
While 1
$line = FileReadLine($file)
If @error = -1 Then ExitLoop
$linenumber += 1
MsgBox(0, "", $line)
Wend
FileClose($file)

[millisys]

Thank you Nessie,

In order to show both todays student name and tomorrows student name, would you write it like this?

#include <File.au3>
$file = "test.txt"
Local $aRecords
If Not _FileReadToArray($file, $aRecords) Then
    MsgBox(4096, "Error", " Error reading log to Array   error:" & @error)
    Exit
EndIf
For $x = 1 To $aRecords[0]
$array0 = StringSplit($aRecords[$x],",")
$array1 = StringSplit($aRecords[$x+1],",")
    MsgBox(0, 'Record:' & $x, "$today's student name = " & $array0[2] & @CRLF & "tomorrow's student name = " & $array1[2])
Next

If I want to show a day 20 days in the future, can I do it inline within the MsgBox function without having to create an $array21?

[millisys]

Thank you Werty,

I would like to be able to view the current line and the next line simultaneously.

[millisys]

Thank you for the explanation BrewManNH.

What is the appropriate circumstance to use the FileReadLine() function?

[BrewManNH]

You'd use it to read a file in a loop, or to read a specific line in a file.

To read your file I'd use the script you posted last, and adapt it as needed. To read 20 days into it, you'd read $aRecords[19], that should be the line 20 days from the start of the file.

[millisys]

Thank you for your help BewManNH

[guinness]

You might want to look at UBound in the help file, this will be able to check the number of dimensions in the array. Therefore if there are only 20 lines, checking the 21st won't invoke an 'out of bounds error'.

[millisys]

Thank you Guinness. I received the 'out of bounds error'and was wondering how to resolve it. I will check out the UBound() function.