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digitalmars.D.learn - Struggling with wchar[] to string conversion

reply Stefan <stefanliebig web.de> writes:
Hi,

I am using dmd2.081.1 on windows building a 32 bit executable.

I am trying to find out how many instances of the same program 
are running. Therefor I use the core.sys.windows.tlhelp32 module.

With the CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) and 
Process32First/Process32Next I iterate over all processes and for 
each process I iterate with 
CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, dwPID) and 
Module32First/Module32Next over all modules of a process.
The Model32First/..Next fill a MODULEENTRY32 structure which 
contains a szExePath member that is a wchar[260].
Converting this to a string succeeds (compiler does not complain) 
with
me32.szExePath.text
However, comparing this with the result of thisExePath() 
(std.file) never succeeds although the two string values when 
written with writeln() appear to be the same.

This drives me crazy!

Any ideas?

Tschüß,
Stefan
Jan 19
next sibling parent Jack <jckj33 gmail.com> writes:
On Tuesday, 19 January 2021 at 15:32:12 UTC, Stefan wrote:
 Hi,

 I am using dmd2.081.1 on windows building a 32 bit executable.

 I am trying to find out how many instances of the same program 
 are running. Therefor I use the core.sys.windows.tlhelp32 
 module.

 With the CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) and 
 Process32First/Process32Next I iterate over all processes and 
 for each process I iterate with 
 CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, dwPID) and 
 Module32First/Module32Next over all modules of a process.
 The Model32First/..Next fill a MODULEENTRY32 structure which 
 contains a szExePath member that is a wchar[260].
 Converting this to a string succeeds (compiler does not 
 complain) with
 me32.szExePath.text
 However, comparing this with the result of thisExePath() 
 (std.file) never succeeds although the two string values when 
 written with writeln() appear to be the same.

 This drives me crazy!

 Any ideas?

 Tschüß,
 Stefan
How are you trying to do such version? if member is of wchar[] get the .ptr and so that you have the memory pointer to operate with import std.stdio; import core.stdc.stddef : wchar_t; import core.sys.windows.windows; void main() { wchar[MAX_PATH] buffer; GetModuleFileName(NULL, buffer.ptr, MAX_PATH); auto s = LPWSTRToDString(buffer.ptr); writeln(s); } // try-catch so that we can mark it as nothrow string LPWSTRToDString(T)(T s) nothrow if(is(T == LPWSTR) || is(T == wchar_t*) || is(T == const(wchar)*)) { import std.conv : to; import std.string : fromStringz; try { return to!(string)(s.fromStringz); } catch(Exception e) { // do your error-handling here return ""; } }
Jan 19
prev sibling parent Adam D. Ruppe <destructionator gmail.com> writes:
On Tuesday, 19 January 2021 at 15:32:12 UTC, Stefan wrote:

 contains a szExePath member that is a wchar[260].
 Converting this to a string succeeds (compiler does not 
 complain) with
 me32.szExePath.text
You need to slice it on length. That default conversion will include all 260 chars. So you probably need to scan it for zeroes with wstrlen or whatever first.
Jan 19