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Adding string$ variable and string together
Posted: Sat Jan 19, 2008 11:04 pm
by PresFox
Hello
I am trying to compile this:
Code: Select all
runprogram(configvalue$(0)+"mysqld-nt.exe")
configvalue$(0) holds the path, mysqld-nt.exe is the filename. However, this doesnt work, what is the way to get string variables and strings together?
Regards
Posted: Sat Jan 19, 2008 11:11 pm
by AND51
Maybe the path does not end with a backslash.
Example:
Code: Select all
path$="C:\WINDOWS"
file$="notepad.exe"
Debug path$+file$
RunProgram(path$+file$) ; DOESN'T WORK
This won't work, because every path in PureBasic usually ends with a trailing Backslash!
Two codes how to check+correct this mistake:
Code: Select all
path$="C:\WINDOWS"
If Right(path$, 1) <> "\"
path$+"\"
EndIf
Debug path$
Shorter, but Windows-Only:
Code: Select all
path$="C:\WINDOWS"
PathAddBackslash_(@path$)
Debug path$
Both codes do the same. The second code uses API, so it should be faster, but it's only available on Windows. If you use the second code, don't forget the @ in front of the variable name!
PathAddBackslash_() expects the pointer to the variable, that's why you must type the @.
If a missing backslash is
not the reason, the variable could be emptry or the path/file doesn't exist. Another reason might be insufficient rights or ressources to execute the destination program.
Posted: Sat Jan 19, 2008 11:21 pm
by PresFox
Got it fixed, thank you for your help
Posted: Sat Jan 19, 2008 11:31 pm
by AND51
No problem, mate.
Posted: Sat Jan 19, 2008 11:36 pm
by freak
The API code is dangerous, as it will write over the end of the PB allocated memory.
You are asking for trouble with that one.
Posted: Sun Jan 20, 2008 1:09 am
by AND51
Oh, you mean the API replaces the trailing NULL with a Backslash?
I though this almost, but I wasn't sure. Although I never had problem with it, I now tend to use the PB code then.
Thank you for this information!
Posted: Sun Jan 20, 2008 2:10 am
by PB
@AND51: See this post where PathAddBackslash was discussed in detail:
http://www.purebasic.fr/english/viewtopic.php?t=25578