processutils.pas

{ Process utility unit. Extends TProcess.
Not unicode-aware (change this when FPC becomes so).

Copyright (C) 2012-2014 Ludo Brands, Reinier Olislagers

This unit is licensed as modified LGPL or MIT, at your choice. Licenses below
}
{
This library is free software; you can redistribute it and/or modify it
under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version with the following modification:

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent modules,and
to copy and distribute the resulting executable under terms of your choice,
provided that you also meet, for each linked independent module, the terms
and conditions of the license of that module. An independent module is a
module which is not derived from or based on this library. If you modify
this library, you may extend this exception to your version of the library,
but you are not obligated to do so. If you do not wish to do so, delete this
exception statement from your version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
for more details.

You should have received a copy of the GNU Library General Public License
along with this library; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
}
{
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
}
unit processutils;

{$mode objfpc}{$H+}
{not $DEFINE DEBUGCONSOLE} //define debug to get writeln output of commands called

interface

uses
  Classes, SysUtils, process, strutils;

const
  // Internal error code/result codes:
  PROC_INTERNALERROR=-1; // error while running process code in this unit
  PROC_INTERNALEXCEPTION=-2; //exception while running process code in this unit
  {$IFDEF MSWINDOWS}
  PATHVARNAME = 'Path'; //Name for path environment variable
  {$ELSE}
  //Unix/Linux
  PATHVARNAME = 'PATH';
  {$ENDIF MSWINDOWS}

type
  TProcessEx = class; //forward
  TDumpFunc = procedure (Sender:TProcessEx; output:string);
  TDumpMethod = procedure (Sender:TProcessEx; output:string) of object;
  TErrorFunc = procedure (Sender:TProcessEx;IsException:boolean);
  TErrorMethod = procedure (Sender:TProcessEx;IsException:boolean) of object;

  { TProcessEnvironment }
  TProcessEnvironment = class(TObject)
    private
      FEnvironmentList:TStringList;
      FCaseSensitive:boolean;
      function GetVarIndex(VarName:string):integer;
    public
      // Get environment variable
      function GetVar(VarName:string):string;
      // Set environment variable
      procedure SetVar(VarName,VarValue:string);
      // List of all environment variables (name and value)
      property EnvironmentList:TStringList read FEnvironmentList;
      constructor Create;
      destructor Destroy; override;
    end;

  { TProcessEx }

  TProcessEx = class(TProcess)
    private
      FExceptionInfoStrings: TstringList;
      FExitStatus: integer; //result code/exit status that executable returned with
      FOnError: TErrorFunc;
      FOnErrorM: TErrorMethod;
      FOnOutput: TDumpFunc;
      FOnOutputM: TDumpMethod;
      FOutputStrings: TstringList;
      FOutStream: TMemoryStream;
      FProcessEnvironment:TProcessEnvironment;
      function GetResultingCommand: string;
      function GetExceptionInfo: string;
      function GetOutputString: string;
      function GetOutputStrings: TstringList;
      function GetParametersString: String;
      function GetProcessEnvironment: TProcessEnvironment;
      procedure SetOnError(AValue: TErrorFunc);
      procedure SetOnErrorM(AValue: TErrorMethod);
      procedure SetOnOutput(AValue: TDumpFunc);
      procedure SetOnOutputM(AValue: TDumpMethod);
    public
      // Run executable with parameters etc. Comes in place of inherited execute.
      {%H-}procedure Execute;
      // Executable+parameters. Use Executable and Parameters/ParametersString to assign
      property ResultingCommand: string read GetResultingCommand;
      // All environment variables, e.g. PATH
      property Environment:TProcessEnvironment read GetProcessEnvironment;
      property ExceptionInfo:string read GetExceptionInfo;
      property ExceptionInfoStrings:TstringList read FExceptionInfoStrings;
      // Return code/exit status that the process returned with. Often 0 for success.
      property ExitStatus:integer read FExitStatus;
      // Use callback to catch error messages
      property OnError:TErrorFunc read FOnError write SetOnError;
      // Use callback to catch error messages
      property OnErrorM:TErrorMethod read FOnErrorM write SetOnErrorM;
      property OnOutput:TDumpFunc read FOnOutput write SetOnOutput;
      property OnOutputM:TDumpMethod read FOnOutputM write SetOnOutputM;
      property OutputString:string read GetOutputString;
      property OutputStrings:TstringList read GetOutputStrings;
      constructor Create(AOwner : TComponent); override;
      destructor Destroy; override;
    end;

// Convenience functions

// Runs command, returns result code. Negative codes are processutils internal error codes
function ExecuteCommand(Commandline: string; Verbose:boolean): integer; overload;
// Runs command, returns result code. Negative codes are processutils internal error codes
function ExecuteCommand(Commandline: string; var Output:string; Verbose:boolean): integer; overload;
// Runs command, returns result code. Negative codes are processutils internal error codes
function ExecuteCommandInDir(Commandline, Directory: string; Verbose:boolean): integer; overload;
// Runs command, returns result code. Negative codes are processutils internal error codes
function ExecuteCommandInDir(Commandline, Directory: string; var Output:string; Verbose:boolean): integer; overload;
// Runs command, returns result code. Negative codes are processutils internal error codes
// PrependPath is prepended to existing path. If empty, keep current path
function ExecuteCommandInDir(Commandline, Directory: string; var Output:string; Verbose:boolean; PrependPath: string): integer; overload;
// Writes output to console
procedure DumpConsole(Sender:TProcessEx; output:string);



implementation

{ TProcessEx }

function TProcessEx.GetOutputString: string;
begin
  result:=OutputStrings.Text;
end;

function TProcessEx.GetOutputStrings: TstringList;
begin
  if (FOutputStrings.Count=0) and (FOutStream.Size>0) then
    begin
    FOutStream.Position := 0;
    FOutputStrings.LoadFromStream(FOutStream);
    end;
  result:=FOutputStrings;
end;

function TProcessEx.GetParametersString: String;
begin
  result:=AnsiReplaceStr(Parameters.text, LineEnding, ' ');
end;

function TProcessEx.GetExceptionInfo: string;
begin
  result:=FExceptionInfoStrings.Text;
end;

function TProcessEx.GetResultingCommand: string;
var i:integer;
begin
  //this is not the command as executed. The quotes are surrounding individual params.
  //the actual quoting is platform dependent
  //perhaps better to use another quoting character to make this clear to the user.
  result:=Executable;
  for i:=0 to Parameters.Count-1 do
    result:=result+' "'+Parameters[i]+'"';
end;

function TProcessEx.GetProcessEnvironment: TProcessEnvironment;
begin
  If not assigned(FProcessEnvironment) then
    FProcessEnvironment:=TProcessEnvironment.Create;
  result:=FProcessEnvironment;
end;

procedure TProcessEx.SetOnError(AValue: TErrorFunc);
begin
  if FOnError=AValue then Exit;
  FOnError:=AValue;
end;

procedure TProcessEx.SetOnErrorM(AValue: TErrorMethod);
begin
  if FOnErrorM=AValue then Exit;
  FOnErrorM:=AValue;
end;

procedure TProcessEx.SetOnOutput(AValue: TDumpFunc);
begin
  if FOnOutput=AValue then Exit;
  FOnOutput:=AValue;
end;

procedure TProcessEx.SetOnOutputM(AValue: TDumpMethod);
begin
  if FOnOutputM=AValue then Exit;
  FOnOutputM:=AValue;
end;

procedure TProcessEx.Execute;

  function ReadOutput: boolean;

  const
    BufSize = 4096;
  var
    Buffer: array[0..BufSize - 1] of byte;
    ReadBytes: integer;
  begin
    Result := False;
    while Output.NumBytesAvailable > 0 do
    begin
      ReadBytes := {%H-}Output.Read(Buffer, BufSize);
      FOutStream.Write(Buffer, ReadBytes);
      if Assigned(FOnOutput) then
        FOnOutput(Self,copy(pchar(@buffer[0]),1,ReadBytes));
      if Assigned(FOnOutputM) then
        FOnOutputM(Self,copy(pchar(@buffer[0]),1,ReadBytes));
      Result := True;
    end;
  end;

begin
  try
    // "Normal" linux and DOS exit codes are in the range 0 to 255.
    // Windows System Error Codes are 0 to 15999
    // Use negatives for internal errors.
    FExitStatus:=PROC_INTERNALERROR;
    FExceptionInfoStrings.Clear;
    FOutputStrings.Clear;
    FOutStream.Clear;
    if Assigned(FProcessEnvironment) then
      inherited Environment:=FProcessEnvironment.EnvironmentList;
    Options := Options +[poUsePipes, poStderrToOutPut];
    if Assigned(FOnOutput) then
      FOnOutput(Self,'Executing : '+ResultingCommand+' (working dir: '+ CurrentDirectory +')'+ LineEnding);
    if Assigned(FOnOutputM) then
      FOnOutputM(Self,'Executing : '+ResultingCommand+' (working dir: '+ CurrentDirectory +')'+ LineEnding);

    try
      if CurrentDirectory<>'' then
      begin
        // Avoid unpredictable behaviour as well as
        // OSX bug 26706 (fixed in FPC trunk)
        if not(DirectoryExists(CurrentDirectory)) then
        begin
          FExitStatus:=PROC_INTERNALEXCEPTION;
          FExceptionInfoStrings.Add('Invalid directory: '+CurrentDirectory);
          FExitStatus:=PROC_INTERNALEXCEPTION;
          if (Assigned(OnError) or Assigned(OnErrorM)) then
            OnError(Self,false)
          else
            OnErrorM(Self,false);
          exit;
        end;
      end;
      inherited Execute;
      while Running do
      begin
        if not ReadOutput then
          Sleep(50);
      end;
      ReadOutput;

      FExitStatus:=inherited ExitStatus;
    except
      // Leave exitstatus as proc_internalerror
      // This should handle calling non-existing application etc.
      // Note also bug 22055 TProcess ExitStatus is zero when the called process Seg Faults
    end;

    if (FExitStatus<>0) and (Assigned(OnError) or Assigned(OnErrorM))  then
      if Assigned(OnError) then
        OnError(Self,false)
      else
        OnErrorM(Self,false);
  except
    on E: Exception do
    begin
    FExceptionInfoStrings.Add('Exception calling '+Executable+' '+Parameters.Text);
    FExceptionInfoStrings.Add('Details: '+E.ClassName+'/'+E.Message);
    FExitStatus:=PROC_INTERNALEXCEPTION;
    if (Assigned(OnError) or Assigned(OnErrorM)) then
      OnError(Self,false)
    else
      OnErrorM(Self,false);
    end;
  end;
end;

constructor TProcessEx.Create(AOwner : TComponent);
begin
  inherited;
  FExceptionInfoStrings:= TstringList.Create;
  FOutputStrings:= TstringList.Create;
  FOutStream := TMemoryStream.Create;
end;

destructor TProcessEx.Destroy;
begin
  FExceptionInfoStrings.Free;
  FOutputStrings.Free;
  FOutStream.Free;
  If assigned(FProcessEnvironment) then
    FProcessEnvironment.Free;
  inherited Destroy;
end;

{ TProcessEnvironment }

function TProcessEnvironment.GetVarIndex(VarName: string): integer;
var
  idx:integer;

  function ExtractVar(VarVal:string):string;
  begin
    result:='';
    if length(Varval)>0 then
      begin
      if VarVal[1] = '=' then //windows
        delete(VarVal,1,1);
      result:=trim(copy(VarVal,1,pos('=',VarVal)-1));
      if not FCaseSensitive then
        result:=UpperCase(result);
      end
  end;

begin
  if not FCaseSensitive then
    VarName:=UpperCase(VarName);
  idx:=0;
  while idx<FEnvironmentList.Count  do
    begin
    if VarName = ExtractVar(FEnvironmentList[idx]) then
      break;
    idx:=idx+1;
    end;
  if idx<FEnvironmentList.Count then
    result:=idx
  else
    result:=-1;
end;

function TProcessEnvironment.GetVar(VarName: string): string;
var
  idx:integer;

  function ExtractVal(VarVal:string):string;
  begin
    result:='';
    if length(Varval)>0 then
      begin
      if VarVal[1] = '=' then //windows
        delete(VarVal,1,1);
      result:=trim(copy(VarVal,pos('=',VarVal)+1,length(VarVal)));
      end
  end;

begin
  idx:=GetVarIndex(VarName);
  if idx>0 then
    result:=ExtractVal(FEnvironmentList[idx])
  else
    result:='';
end;

procedure TProcessEnvironment.SetVar(VarName, VarValue: string);
var
  idx:integer;
  s:string;
begin
  idx:=GetVarIndex(VarName);
  s:=trim(Varname)+'='+trim(VarValue);
  if idx>0 then
    FEnvironmentList[idx]:=s
  else
    FEnvironmentList.Add(s);
end;

constructor TProcessEnvironment.Create;
var
  i: integer;
begin
  FEnvironmentList:=TStringList.Create;
  {$ifdef WINDOWS}
  FCaseSensitive:=false;
  {$else}
  FCaseSensitive:=true;
  {$endif WINDOWS}
  // GetEnvironmentVariableCount is 1 based
  for i:=1 to GetEnvironmentVariableCount do
    EnvironmentList.Add(trim(GetEnvironmentString(i)));
end;

destructor TProcessEnvironment.Destroy;
begin
  FEnvironmentList.Free;
  inherited Destroy;
end;

procedure DumpConsole(Sender:TProcessEx; output:string);
begin
  write(output);
end;

function ExecuteCommand(Commandline: string; Verbose: boolean): integer;
var
  s:string='';
begin
  Result:=ExecuteCommandInDir(Commandline,'',s,Verbose);
end;

function ExecuteCommand(Commandline: string; var Output: string;
  Verbose: boolean): integer;
begin
  Result:=ExecuteCommandInDir(Commandline,'',Output,Verbose);
end;

function ExecuteCommandInDir(Commandline, Directory: string; Verbose: boolean
  ): integer;
var
  s:string='';
begin
  Result:=ExecuteCommandInDir(Commandline,Directory,s,Verbose);
end;

function ExecuteCommandInDir(Commandline, Directory: string;
  var Output: string; Verbose: boolean): integer;
begin
  Result:=ExecuteCommandInDir(CommandLine,Directory,Output,Verbose,'');
end;

function ExecuteCommandInDir(Commandline, Directory: string;
  var Output: string; Verbose: boolean; PrependPath: string): integer;
var
  OldPath: string;
  PE:TProcessEx;
  s:string;

  function GetFirstWord:string;
  var
    i:integer;
    LastQuote:char=#0;
    InQuote:boolean;
  const
    QUOTES = ['"',''''];
  begin
  Commandline:=trim(Commandline);
  i:=1;
  InQuote:=false;
  while (i<=length(Commandline)) and (InQuote or (Commandline[i]>' ')) do
    begin
    // Check first and last quote:
    if Commandline[i] in QUOTES then
      if InQuote then
        begin
        if Commandline[i]=LastQuote then
          begin
          InQuote:=false;
          delete(Commandline,i,1);
          i:=i-1;
          end;
        end
      else
        begin
        InQuote:=True;
        LastQuote:=Commandline[i];
        delete(Commandline,i,1);
        i:=i-1;
        end;
    i:=i+1;
    end;
  // Copy found word and remove it from remaining command line
  result:=trim(copy(Commandline,1,i));
  delete(Commandline,1,i);
  end;

begin
  PE:=TProcessEx.Create(nil);
  try
    if Directory<>'' then
      PE.CurrentDirectory:=Directory;

    // Prepend specified PrependPath if needed:
    if PrependPath<>'' then
    begin
      OldPath:=PE.Environment.GetVar(PATHVARNAME);
      if OldPath<>'' then
        PE.Environment.SetVar(PATHVARNAME, PrependPath+PathSeparator+OldPath)
      else
        PE.Environment.SetVar(PATHVARNAME, PrependPath);
    end;
    PE.Executable:=GetFirstWord;
    s:=GetFirstWord;
    while s<>'' do
      begin
      PE.Parameters.Add(s);
      s:=GetFirstWord;
      end;
    PE.ShowWindow := swoHIDE;
    if Verbose then
      PE.OnOutput:=@DumpConsole;
    {$IFDEF DEBUGCONSOLE}
    writeln('ExecuteCommandInDir: executable '+PE.Executable);
    writeln('ExecuteCommandInDir: params     '+PE.Parameters.Text);
    {$ENDIF DEBUGCONSOLE}
    PE.Execute;

    Output:=PE.OutputString;
    Result:=PE.ExitStatus;
    {$IFDEF DEBUGCONSOLE}
    writeln('ExecuteCommandInDir: exit status: '+inttostr(Result));
    {$ENDIF DEBUGCONSOLE}
  finally
    PE.Free;
  end;
end;

end.