fpc

问题 I'm just wondering how it's possible to do type checking in pascal? I have been searching for hours now but I haven't been able to find anything useful. Example: var number: Integer; begin write('Enter a number: '); read(number); if {How am I supposed to check if 'number' is an Integer here?} then writeln(number) else writeln('Invalid input') end. 回答1: You are actually hitting the I/O type checking. You can work around this by disabling it temporarily and then checking the result: {$I-} /

问题 I've had a look at /etc/fpc.cfg and there is mention to some defines: FPCAPACHE_1_3 FPCAPACHE_2_0 Then in the fcl-web examples there is mention to: Apache1_3 The only one I've found is on the apr.pas on both these files: /usr/share/fpcsrc/2.4.0/packages/httpd20/src/apr/apr.pas /usr/share/fpcsrc/2.4.0/packages/httpd22/src/apr/apr.pas So how does the compiler decide what version of APR to compile? 回答1: If you enable the right one of those conditionals/directives afaik, the rest of the fpc.cfg

问题 How can I link a FPC .o from a library to a Delphi executable. When I try to link the following code I get a bunch of unsatisfied forward or external declarations. library project1; {$mode objfpc}{$H+} uses Classes { you can add units after this }; function Test: Integer; begin Result := -1; end; begin end. [dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$SYSTEM' [dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration:

问题 My specs: OS: Ubuntu 10.04 LTS amd64 fpc: 2.4.0 lazarus: 0.9.28 I'm trying to compile a WebLaz project just by creating one and then compiling. Somehow the compiler gets all lost when determinig witch httpd and fpapache Units to use. I've found similar problems in the forums: mod_helloworld.lpr Can't find fpapache Unit ... I NEED HELP with fpweb ... After trying some of the solutions provided there I'm still at this point: Project compiles fine if I only have httpd22 under the Compiled units

问题 Using: Lazarus 1.2.0; Windows 32-bit application I have created a custom component derived from TCustomPanel and contains some TEdit controls. At runtime, when I try to set the Text property of an edit control in my component, I get a runtime error. This is the error: Project project1 raised exception class 'External: SIGSEGV'. In file '.\include\control.inc' at line 3246: GetTextMethod := TMethod(@Self.GetTextBuf); I Googled and could not find anybody else reporting this error specifically

问题 I finally had success compiling a "blank" Apache module, but now I've hit a rather annoying snag. I want to communicate with a MongoDB server and I opted for the only lib around for FreePascal/Lazarus, pebongo. Dependency for pebongo is synapse. Somehow I'm getting "/usr/lib/apache2/modules/mod_visius.so: undefined symbol: WSRegisterCustomImageList" when loading my module into Apache. I've tracked down the symbols onto Menus.pp, I think, and lazarusall(something) also plays a role in this.

问题 I asked on the Lazarus programming forum how to open a physical disk. I want to allow the user to select physical disks from their system when they click a "Select Disk" button. There are some examples here at Stack Overflow that are similar but not quite the same (such as Delphi - Using DeviceIoControl passing IOCTL_DISK_GET_LENGTH_INFO to get flash media physical size (Not Partition)). There are lots of C and C++ examples of using CreateFile (in the documentation and especially an example

问题 This is my first time on this site. Usually, I have no problem to found replies in the old posts but I don't success with my actual problem. I would like to know how use RTTI functions to know at running time the properties/members of a record under Lazarus/FPC? I know how to do it for a class (Tpersistent descendant and published properties) but not for FPC. Some links indicates how to do it under Delphi (From D2010), but I don't know how to transpose it under Lazarus. Thanks in advance for

问题 I'm using fpc compiler and I want to remove this warning. I've read fpc's options but I can't find how to do that. Is this possible? it appear when I run command: fpc foo.pas out: Target OS: Linux for i386 Compiling foo.pas Linking p2 /usr/bin/ld: warning: link.res contains output sections; did you forget -T? 79 lines compiled, 0.1 sec 回答1: It's a bug in certain LD versions. Just ignore it for now, or see if your distro has an update for your LD. (package binutils) http://www.freepascal.org