Dunyunkin
8th February 2006 14:48 UTC

Path concatenation
Call me Thicky McThick but... how do I concatenate path elements together?

I've got a path string and I want to add a subdirectory to that string but I don't know if it has a trailing backslash (\) or not. Easy-peasy - except I can't see how to check the last character of the source string?

I'm probably missing the obvious again, but I can't see anything in the documentation or by searching this forum.

glory_man
8th February 2006 15:35 UTC

Use StrCpy instruction to concatenate strings, StrCmp to check last symbol.

Dunyunkin
8th February 2006 15:40 UTC

Tried that but can't see any way to specify an offset to StrCmp (or even to work out the length of the string)

glory_man
8th February 2006 15:44 UTC

4.9.8.1 StrCpy
user_var(destination) str [maxlen] [start_offset]
Sets the user variable $x with str. Note that str can contain other variables, or the user variable being set (concatenating strings this way is possible, etc). If maxlen is specified, the string will be a maximum of maxlen characters (if maxlen is negative, the string will be truncated abs(maxlen) characters from the end). If start_offset is specified, the source is offset by it (if start_offset is negative, it will start abs(start_offset) from the end of the string).

StrCpy $0 "a string" # = "a string"
StrCpy $0 "a string" 3 # = "a s"
StrCpy $0 "a string" -1 # = "a strin"
StrCpy $0 "a string" "" 2 # = "string"
StrCpy $0 "a string" "" -3 # = "ing"
StrCpy $0 "a string" 3 -4 # = "rin"

Dunyunkin
8th February 2006 16:09 UTC

I had seen that but you made me think about solving the problem backwards - so rather than trying to compare a substring; copy out the bit to be tested and then compare that... A bit round about but this seems to work:

StrCpy $2 $1 "" -1
StrCmp $2 "\" +2
StrCpy $1 "$1\"
StrCpy $INSTDIR "$1New Sub Dir"