[BUSH User Guide]
 
Home Page Introduction Tutorials Reference Packages Hacking
 
  Packages  
4.1 Using Packages
4.2 text_io (Console I/O)
4.3 text_io (File I/O)
4.4 sound
4.5 source_info
4.6 System
4.7 numerics
4.8 strings
4.9 command_line
4.10 lock_files
4.11 cgi
4.12 calendar
4.13 units
4.14 arrays
4.15 files
4.16 db (Database)
4.17 stats
4.18 pen
4.19 mysql
4.20 os
4.21 directory_operations
 
This part of the guide contains detailed descriptions of the BUSH built-in packages.
 

4.9 command_line Package

The command_line package provides communication between a script and the calling program. This package sets the exit status and processes command line option switches. command_line contains following routines:

GCC Ada equivalent: Ada.Command_Line


n := command_line.argument_count

return the number of script arguments (the same as $#). Exclude BUSH option switches.
Example: if command_line.argument_count > 0 then ...
Ada Equivalent: Ada.Command_Line.Argument_Count
Parameters:
n return value natural required the argument count


s := command_line.argument( p )

return a command line argument (the same as $n where n is a number). The arguments do not include option swithes interpreted by BUSH.
Example: put_line( "First argument is " & command_line.argument( 1 ) );
Ada Equivalent: Ada.Command_Line.Argument
Parameters:
p in positive required the argument number
s return value string required the value of the argument

A bad argument number will raise an exception.


s := command_line.command_name

return the the name of the script or BUSH interpreter (the same as $0)
Example: put_line( command_line.command_name & " is this script" );
Ada Equivalent: Ada.Command_Line.Command_Name
Parameters:
s return value string required the name of the script or BUSH interpreter


n := command_line.environment.environment_count

return the number of variables in the operating system environment.
Example: for i in 1..command_line.environment.environment_count loop ...
Ada Equivalent: Ada.Command_Line.Environment.Environment_Count
Parameters:
n return value natural required the argument count


s := command_line.environment.environment_value( p )

return an operating system environment value in the form of "VAR=value".
Example: put_line( "First value is " & command_line.environment.environment_value( 1 ) );
Ada Equivalent: Ada.Command_Line.Environment.Environment_Value
Parameters:
p in positive required the argument number
s return value string required the value of the argument

A bad environment value number will raise an exception.


command_line.set_exit_status( n )

set the status code to be returned by the script to the calling program. (To read the exit status, use os.status.)
Example: command_line.set_exit_status( 0 ); -- all is well
Ada Equivalent: Ada.Command_Line.Set_Exit_Status
Parameters:
i in short_short_integer required the status code to return (0 for no error)

End of Document

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