Replace 1st piece in string, then delete other parts

From NSIS Wiki

Author: Afrow UK (talk, contrib)

[edit] Description

This will replace the first piece of text it finds (e.g. hello) with (e.g. goodbye) and then if it finds any more (e.g. hello)'s then it will delete them.

[edit] Usage

Push "called" ; string to replace other
Push "hello" ; string to be replaced
Push "hello I'm hello hello hello Afrow UK"
 Call StrReplaceOnce
Pop $R0

$R0 = "I'm called Afrow UK"

[edit] The Function

Function StrReplaceOnce
Exch $0
Exch
Exch $1
Exch
Exch 2
Exch $2
Exch 2
Push $3
Push $4
Push $5
StrCpy $3 0
StrLen $5 $1
loop:
  IntOp $3 $3 + 1
  StrCpy $4 $0 $5 -$3
  StrCmp $4 "" done
  StrCmp $4 $1 0 loop
  IntOp $5 $3 - $5
  StrCpy $4 $0 -$3
  StrCpy $5 $0 $5 -$5
  StrCpy $4 $4$2$5
  StrCpy $0 $4
  StrCpy $3 0
  StrLen $5 $1
loop2:
  IntOp $3 $3 + 1
  StrCpy $4 $0 $5 -$3
  StrCmp $4 "" done
  StrCmp $4 $1 0 loop2
  IntOp $5 $3 - $5
  IntOp $5 $5 - 1
  StrCpy $4 $0 -$3
  StrCpy $5 $0 $5 -$5
  StrCpy $4 $4$5
  StrCpy $0 $4
  StrCpy $3 0
  StrLen $5 $1
Goto loop2
done:
  StrLen $1 $0
  StrCpy $2 $0 1 -$1
  StrCmp $2 " " 0 +3
  IntOp $1 $1 - 1
  StrCpy $0 $0 $1 -$1
Pop $5
Pop $4
Pop $3
Pop $2
Pop $1
Exch $0
FunctionEnd

This was written from scratch by Afrow UK on the 2nd May 2003 at 10pm. Completed on 3rd May at 12:05am

-Stu