ncbiexec.hpp

ncbi源码

/*
 * ===========================================================================
 * PRODUCTION $Log: ncbiexec.hpp,v $
 * PRODUCTION Revision 1000.1  2004/04/21 14:34:43  gouriano
 * PRODUCTION PRODUCTION: UPGRADED [CATCHUP_003] Dev-tree R1.13
 * PRODUCTION
 * ===========================================================================
 */

#ifndef CORELIB__NCBIEXEC__HPP
#define CORELIB__NCBIEXEC__HPP

/*  $Id: ncbiexec.hpp,v 1000.1 2004/04/21 14:34:43 gouriano Exp $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software/database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software/database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Author:  Vladimir Ivanov
 *
 *
 */

/// @file ncbiexec.hpp 
/// Defines a portable execute class.


#include <corelib/ncbistd.hpp>
#include <corelib/ncbi_limits.hpp>


/** @addtogroup Exec
 *
 * @{
 */


BEGIN_NCBI_SCOPE


/////////////////////////////////////////////////////////////////////////////
///
/// CExecException --
///
/// Define exceptions generated by CExec.
///
/// CExecException inherits its basic functionality from
/// CErrnoTemplException<CCoreException> and defines additional error codes
/// for errors generated by CExec.

class NCBI_XNCBI_EXPORT CExecException : 
                        public CErrnoTemplException<CCoreException>
{
public:
    /// Error types that CExec can generate.
    enum EErrCode {
        eSystem,        ///< System error
        eSpawn          ///< Spawn error
    };

    /// Translate from the error code value to its string representation.
    virtual const char* GetErrCodeString(void) const
    {
        switch (GetErrCode()) {
        case eSystem: return "eSystem";
        case eSpawn:  return "eSpawn";
        default:      return CException::GetErrCodeString();
        }
    }

    // Standard exception boilerplate code.
    NCBI_EXCEPTION_DEFAULT(CExecException,
                           CErrnoTemplException<CCoreException>);
};



/////////////////////////////////////////////////////////////////////////////
///
/// CExec --
///
/// Define portable exec class.
///
/// Defines the different ways a process can be spawned.
/// NOTE:  In the eNoWait and eDetach modes Spawn functions returns a process
///        handle. On MS Windows it is a real process handle of type HANDLE.
///        On UNIX it is a process identifier (pid).

class NCBI_XNCBI_EXPORT CExec
{
public:

    /// Which exec mode the spawned process is called with.
    enum EMode {
        eOverlay = 0, ///< Overlays calling process with new process,
                      ///< destroying calling process. 
        eWait    = 1, ///< Suspends calling thread until execution of new 
                      ///< process is complete (synchronous operation).
        eNoWait  = 2, ///< Continues to execute calling process concurrently 
                      ///< with new process (asynchronous process).
        eDetach  = 3  ///< Continues to execute calling process; new process 
                      ///< is run in background with no access to console or 
                      ///< keyboard; calls to Wait() against new process will
                      ///< fail; this is an asynchronous spawn.
    };

    /// Execute the specified command.
    ///
    /// Execute the command and return the executed command's exit code.
    /// Throw an exception if command failed to execute. If cmdline is a null
    /// pointer, System() checks if the shell (command interpreter) exists and
    /// is executable. If the shell is available, System() returns a non-zero
    /// value; otherwise, it returns 0.
    static int System(const char* cmdline);

    /// Spawn a new process with specified command-line arguments.
    ///
    /// In the SpawnL() version, the command-line arguments are passed
    /// individually. SpawnL() is typically used when number of parameters to
    /// the new process is known in advance.
    ///
    /// Meaning of the suffix "L" in method name:
    /// - The letter "L" as suffix refers to the fact that command-line
    ///   arguments are passed separately as arguments.
    ///
    /// NOTE: At least one argument must be present. This argument is always, 
    /// by convention, the name of the file being spawned (argument with 
    /// number 0).
    /// @param mode
    ///   Mode for running the process.
    /// @param cmdline
    ///   Command-line string.
    /// @param argv
    ///   Argument vector.
    /// @return 
    ///   On success, return:
    ///     - exit code      - in eWait mode.
    ///     - process handle - in eNoWait and eDetach modes.
    ///     - nothing        - in eOverlay mode.   
    ///   Throw an exception if command failed to execute.
    /// @sa
    ///   SpawnLE(), SpawnLP(), SpawnLPE(), SpawnV(), SpawnVE(), SpawnVP(), 
    ///   SpawnVPE().
    static int SpawnL(EMode mode, const char *cmdname, 
                      const char *argv, ... /*, NULL */);

    /// Spawn a new process with specified command-line arguments and
    /// environment settings.
    ///
    /// In the SpawnLE() version, the command-line arguments and environment
    /// pointer are passed individually. SpawnLE() is typically used when
    /// number of parameters to the new process and individual environment 
    /// parameter settings are known in advance.
    ///
    /// Meaning of the suffix "LE" in method name:
    /// - The letter "L" as suffix refers to the fact that command-line
    ///   arguments are passed separately as arguments.
    /// - The letter "E" as suffix refers to the fact that environment pointer,
    ///   envp, is passed as an array of pointers to environment settings to 
    ///   the new process. The NULL environment pointer indicates that the new 
    ///   process will inherit the parents process's environment.
    ///
    /// NOTE: At least one argument must be present. This argument is always, 
    /// by convention, the name of the file being spawned (argument with 
    /// number 0).
    /// @param mode
    ///   Mode for running the process.
    /// @param cmdline
    ///   Command-line string.
    /// @param argv
    ///   Argument vector.
    /// @param ...
    ///   NULL, const char* envp[]
    /// @return 
    ///   On success, return:
    ///     - exit code      - in eWait mode.
    ///     - process handle - in eNoWait and eDetach modes.
    ///     - nothing        - in eOverlay mode.   
    ///   Throw an exception if command failed to execute.
    /// @sa
    ///   SpawnL(), SpawnLP(), SpawnLPE(), SpawnV(), SpawnVE(), SpawnVP(), 
    ///   SpawnVPE().
    static int SpawnLE (EMode mode, const char *cmdname, 
                        const char *argv, ... /*, NULL, const char *envp[] */);

    /// Spawn a new process with variable number of command-line arguments and
    /// find file to execute from the PATH environment variable.
    ///
    /// In the SpawnLP() version, the command-line arguments are passed
    /// individually and the PATH environment variable is used to find the
    /// file to execute. SpawnLP() is typically used when number
    /// of parameters to the new process is known in advance but the exact
    /// path to the executable is not known.
    ///
    /// Meaning of the suffix "LP" in method name:
    /// - The letter "L" as suffix refers to the fact that command-line
    ///   arguments are passed separately as arguments.
    /// - The letter "P" as suffix refers to the fact that the PATH
    ///   environment variable is used to find file to execute - on a Unix
    ///   platform this feature works in functions without letter "P" in
    ///   function name. 
    ///
    /// NOTE: At least one argument must be present. This argument is always, 
    /// by convention, the name of the file being spawned (argument with 
    /// number 0).
    /// @param mode
    ///   Mode for running the process.
    /// @param cmdline
    ///   Command-line string.
    /// @param argv
    ///   Argument vector.
    /// @param ...
    ///   NULL
    /// @return 
    ///   On success, return:
    ///     - exit code      - in eWait mode.
    ///     - process handle - in eNoWait and eDetach modes.
    ///     - nothing        - in eOverlay mode.   
    ///   Throw an exception if command failed to execute.
    /// @sa
    ///   SpawnL(), SpawnLE(), SpawnLPE(), SpawnV(), SpawnVE(), SpawnVP(), 
    ///   SpawnVPE().
    static int SpawnLP(EMode mode, const char *cmdname,
                        const char *argv, ... /*, NULL */);

    /// Spawn a new process with specified command-line arguments, 
    /// environment settings and find file to execute from the PATH
    /// environment variable.
    ///
    /// In the SpawnLPE() version, the command-line arguments and environment
    /// pointer are passed individually, and the PATH environment variable
    /// is used to find the file to execute. SpawnLPE() is typically used when
    /// number of parameters to the new process and individual environment
    /// parameter settings are known in advance, but the exact path to the
    /// executable is not known.
    ///
    /// Meaning of the suffix "LPE" in method name:
    /// - The letter "L" as suffix refers to the fact that command-line
    ///   arguments are passed separately as arguments.