flizebogen
11th August 2009 16:43 UTC

Possible Bug in File Handling
  This Code deletes the content of the File test1.txt if it existed before. I noticed this because of a typo in one of my scripts. Tested with v.2.45 on Vista SP2 64Bit and XP SP3

Outfile test.exe

>Var File1

>Var File2

RequestExecutionLevel user

Section "Main"

   SetOutPath "EXEDIR"

   FileOpen "$File1" "$EXEDIR\test1.txt" w

    StrCpy "$File2" "$EXEDIR\test2.txt"

   FileWrite "$File2" "Hello World"

   FileClose "$File1"

>SectionEnd 

>

Why is the File test1.txt altered? FileWrite is referring to the wrong handle.

pengyou
11th August 2009 17:16 UTC

Why is the File test1.txt altered?

The file is altered because your script contains this line

FileOpen "$File1" "$EXEDIR\test1.txt" w

The Users Manual explains why this happens:

4.9.5.2 FileOpen
user_var(handle output) filename openmode
... The openmode should be one of "r" (read) "w" (write, all contents of file are destroyed) or "a" (append, meaning opened for both read and write, contents preserved).