slangfun.txt

一个C格式的脚本处理函数库源代码,可让你的C程序具有执行C格式的脚本文件

   Get the current working directory

 USAGE
   String_Type getcwd ()

 DESCRIPTION
   The `getcwd' function returns the absolute pathname of the
   current working directory.  If an error occurs or it cannot
   determine the working directory, it returns `NULL' and sets
   `errno' accordingly.

 NOTES
   Under Unix, OS/2, and MSDOS, the pathname returned by this function
   includes the trailing slash character.  Some versions also include
   the drive specifier.

 SEE ALSO
   mkdir, chdir, errno
--------------------------------------------------------------

listdir

 SYNOPSIS
   Get a list of the files in a directory

 USAGE
   String_Type[] listdir (String_Type dir)

 DESCRIPTION
   The `listdir' function returns the directory listing of all the
   files in the specified directory `dir' as an array of strings.
   It does not return the special files `".."' and `"."' as
   part of the list.

 SEE ALSO
   stat_file, stat_is, length
--------------------------------------------------------------

lstat_file

 SYNOPSIS
   Get information about a symbolic link

 USAGE
   Struct_Type lstat_file (String_Type file)

 DESCRIPTION
   The `lstat_file' function behaves identically to `stat_file'
   but if `file' is a symbolic link, `lstat_file' returns
   information about the link itself, and not the file that it
   references.
   
   See the documentation for `stat_file' for more information.

 NOTES
   On systems that do not support symbolic links, there is no
   difference between this function and the `stat_file' function.

 SEE ALSO
   stat_file, readlink
--------------------------------------------------------------

mkdir

 SYNOPSIS
   Create a new directory

 USAGE
   Integer_Type mkdir (String_Type dir, Integer_Type mode)

 DESCRIPTION
   The `mkdir' function creates a directory whose name is specified
   by the `dir' parameter with permissions specified by `mode'.
   Upon success `mkdir' returns zero, or it returns `-1' and
   sets `errno' accordingly.  In particular, if the directory
   already exists, the function will fail and set errno to
   `EEXIST'.

 EXAMPLE

        define my_mkdir (dir)
        {
           if (0 == mkdir (dir, 0777)) return;
           if (errno == EEXIST) return;
           verror ("mkdir %s failed: %s", dir, errno_string (errno));
        }


 NOTES
   The `mode' parameter may not be meaningful on all systems.  On
   systems where it is meaningful, the actual permissions on the newly
   created directory are modified by the process's umask.

 SEE ALSO
   rmdir, getcwd, chdir, fopen, errno
--------------------------------------------------------------

readlink

 SYNOPSIS
   String_Type readlink (String_Type path)

 USAGE
   Get the value of a symbolic link

 DESCRIPTION
   The `readlink' function returns the value of a symbolic link and
   returns it as a string.  Upon failure, NULL is returned and
   `errno' set accordingly.

 NOTES
   Not all systems support this function.

 SEE ALSO
   lstat_file, stat_file, stat_is
--------------------------------------------------------------

remove

 SYNOPSIS
   Delete a file

 USAGE
   Integer_Type remove (String_Type file)

 DESCRIPTION
   The `remove' function deletes a file.  It returns 0 upon
   success, or -1 upon error and sets `errno' accordingly.

 SEE ALSO
   rename, rmdir
--------------------------------------------------------------

rename

 SYNOPSIS
   Rename a file

 USAGE
   Integer_Type rename (String_Type old, String_Type new)

 DESCRIPTION
   The `rename' function renames a file from `old' to `new'
   moving it between directories if necessary.  This function may fail
   if the directories do not refer to the same file system.  It returns
   0 upon success, or -1 upon error and sets `errno' accordingly.

 SEE ALSO
   remove, errno
--------------------------------------------------------------

rmdir

 SYNOPSIS
   Remove a directory

 USAGE
   Integer_Type rmdir (String_Type dir)

 DESCRIPTION
   The `rmdir' function deletes a specified directory.  It returns
   0 upon success or -1 upon error and sets `errno' accordingly.

 NOTES
   The directory must be empty before it can be removed.

 SEE ALSO
   rename, remove, mkdir
--------------------------------------------------------------

stat_file

 SYNOPSIS
   Get information about a file

 USAGE
   Struct_Type stat_file (String_Type file)

 DESCRIPTION
   The `stat_file' function returns information about `file'
   through the use of the system `stat' call.  If the stat call
   fails, the function returns `NULL' and sets errno accordingly.
   If it is successful, it returns a stat structure with the following
   integer fields:

       st_dev
       st_ino
       st_mode
       st_nlink
       st_uid
       st_gid
       st_rdev
       st_size
       st_atime
       st_mtime
       st_ctime

   See the man page for `stat' for a discussion of these fields.

 EXAMPLE
   The following example shows how the `stat_file' function may be
   used to get the size of a file:

        define file_size (file)
        {
           variable st;
           st = stat_file(file);
           if (st == NULL) verror ("Unable to stat %s", file);
           return st.st_size;
        }


 SEE ALSO
   lstat_file, stat_is
--------------------------------------------------------------

stat_is

 SYNOPSIS
   Parse the var{st_mode

 USAGE
   Char_Type stat_is (String_Type type, Integer_Type st_mode)

 DESCRIPTION
   The `stat_is' function returns a signed character value about
   the type of file specified by `st_mode'.  Specifically,
   `type' must be one of the strings:

        "sock"     (socket)
        "fifo"     (fifo)
        "blk"      (block device)
        "chr"      (character device)
        "reg"      (regular file)
        "lnk"      (link)
        "dir"      (dir)

   It returns a non-zero value if `st_mode' corresponds to
   `type'.

 EXAMPLE
   The following example illustrates how to use the `stat_is'
   function to determine whether or not a file is a directory:

        define is_directory (file)
        {
           variable st;
   
           st = stat_file (file);
           if (st == NULL) return 0;
           return stat_is ("dir", st.st_mode);
        }


 SEE ALSO
   stat_file, lstat_file
--------------------------------------------------------------

autoload

 SYNOPSIS
   Load a function from a file

 USAGE
   autoload (String_Type funct, String_Type file)

 DESCRIPTION
    The `autoload' function is used to declare `funct' to the
    interpreter and indicate that it should be loaded from `file' when
    it is actually used.

 EXAMPLE
    Suppose `bessel_j0' is a function defined in the file
    `bessel.sl'.  Then the statement

         autoload ("bessel_j0", "bessel.sl");

    will cause `bessel.sl' to be loaded prior to the execution of
    `bessel_j0'

 SEE ALSO
   evalfile
--------------------------------------------------------------

byte_compile_file

 SYNOPSIS
   Compile a file to byte-code for faster loading.

 USAGE
   byte_compile_file (String_Type file, Integer_Type method)

 DESCRIPTION
   The `byte_compile_file' function byte-compiles `file'
   producing a new file with the same name except a `'c'' is added
   to the output file name.  For example, `file' is
   `"site.sl"', then the function produces a new file named
   `site.slc'.

 NOTES
   The `method' parameter is not used in the current
   implementation.  Its use is reserved for the future.  For now, set
   it to `0'.

 SEE ALSO
   evalfile
--------------------------------------------------------------

eval

 SYNOPSIS
   Interpret a string as slang code

 USAGE
   eval (String_Type expression, [,String_Type namespace])

 DESCRIPTION
   The `eval' function parses a string as S-Lang code and executes the
   result.  If called with the optional namespace argument, then the
   string will be evaluated in the specified namespace.
   
   This is a useful function in many contexts such as dynamically
   generating function definitions where there is no way to generate
   them otherwise.

 EXAMPLE

       if (0 == is_defined ("my_function"))
         eval ("define my_function () { message (\"my_function\"); }");


 SEE ALSO
   is_defined, autoload, evalfile
--------------------------------------------------------------

evalfile

 SYNOPSIS
   Interpret a file containing slang code.

 USAGE
   Integer_Type evalfile (String_Type file, [,String_Type namespace])

 DESCRIPTION
   The `evalfile' function loads `file' into the interpreter
   and executes it.  If called with the optional namespace argument,
   the file will be loaded into the specified namespace, which will be
   created if necessary.  If no errors were encountered, `1' will
   be returned; otherwise, a S-Lang error will be generated and the
   function will return zero.

 EXAMPLE

       define load_file (file)
       {
          ERROR_BLOCK { _clear_error (); }
          () = evalfile (file);
       }


 NOTES
   For historical reasons, the return value of this function is not
   really useful.
   
   The file is searched along an application-defined load-path.  The
   `get_slang_load_path' and `set_slang_load_path' functions
   may be used to set and query the path.

 SEE ALSO
   eval, autoload, set_slang_load_path, get_slang_load_path
--------------------------------------------------------------

get_slang_load_path

 SYNOPSIS
   Get the value of the interpreter's load-path

 USAGE
   String_Type get_slang_load_path ()

 DESCRIPTION
   This function retrieves the value of the delimiter-separated search
   path used for loading files.

 NOTES
   Some applications may not support the built-in load-path searching
   facility provided by the underlying library.

 SEE ALSO
   
--------------------------------------------------------------

set_slang_load_path

 SYNOPSIS
   Set the value of the interpreter's load-path

 USAGE
   set_slang_load_path (String_Type path)

 DESCRIPTION
   This function may be used to set the value of the
   delimiter-separated search path used by the `evalfile' and
   `autoload' functions for locating files.

 EXAMPLE

       public define prepend_to_slang_load_path (p)
       {
          variable s = stat_file (p);
          if (s == NULL) return;
          if (0 == stat_is ("dir", s.st_mode))
            return;
   
          variable d = path_get_delimiter ();
          set_slang_load_path (strcat (p, d, get_slang_load_path ()));
       }


 NOTES
   Some applications may not support the built-in load-path searching
   facility provided by the underlying library.

 SEE ALSO
   get_slang_load_path, path_get_delimiter, evalfile, autoload
--------------------------------------------------------------

get_import_module_path

 SYNOPSIS
   Get the search path for dynamically loadable objects

 USAGE
   String_Type get_import_module_path ()

 DESCRIPTION
   The `get_import_module_path' may be used to get the search path
   for dynamically shared objects.  Such objects may be made accessable
   to the application via the `import' function.

 SEE ALSO
   import, set_import_module_path
--------------------------------------------------------------

import

 SYNOPSIS
   Dynamically link to a specified module

 USAGE
   import (String_Type module [, String_Type namespace])

 DESCRIPTION
   The `import' function causes the run-time linker to dynamically
   link to the shared object specified by the `module' parameter.
   It seaches for the shared object as follows: First a search is
   performed along all module paths specified by the application.  Then
   a search is made along the paths defined via the
   `set_import_module_path' function.  If not found, a search is
   performed along the paths given by the `SLANG_MODULE_PATH'
   environment variable.  Finally, a system dependent search is
   performed (e.g., using the `LD_LIBRARY_PATH' environment
   variable).
   
   The optional second parameter may be used to specify a namespace
   for the intrinsic functions and variables of the module.  If this
   parameter is not present, the intrinsic objects will be placed into
   the global namespace.
   
   This function signals an error if the specified module is not found.

 NOTES
   The `import' function is not available on all systems.

 SEE ALSO
   set_import_module_path, use_namespace, current_namespace, getenv, evalfile
--------------------------------------------------------------

set_import_module_path

 SYNOPSIS
   Set the search path for dynamically loadable objects

 USAGE
   set_import_module_path (String_Type path_list)

 DESCRIPTION
   The `set_import_module_path' may be used to set the search path
   for dynamically shared objects.  Such objects may be made accessable
   to the application via the `import' function.
   
   The actual syntax for the specification of the set of paths will
   vary according to the operating system.  Under Unix, a colon
   character is used to separate paths in `path_list'.  For win32
   systems a semi-colon is used.

 SEE ALSO
   import, get_import_module_path
--------------------------------------------------------------

_NARGS