Command
Returns command line parameters used to call the program
result = Command[$]( [ index ] )
index
Returns the command-line arguments(s).
Command returns command-line arguments passed to the program upon execution.
If index is less than zero (< 0), a space-separated list of all command-line arguments is returned, otherwise, a single argument is returned. A value of zero (0) returns the name of the executable; and values of one (1) and greater return each command-line argument.
If index is greater than the number of arguments passed to the program, the null string ("") is returned.
When the command line is parsed for arguments, everything between double quotes in the parameter list will be considered as a single parameter, and is returned with the double quotes.
By default, filename globbing for arguments (expansion of wildcards to filenames) is used on all ports of FreeBASIC for compatibility. Arguments on the command line containing wildcards are typically not expanded if when no file is matched or if properly quoted. Other special characters for redirection are typically not returned unless properly quoted. Consult the documentation on the shell being used for more information on the proper quoting of command line arguments.
WARNING: By nature of constructor precedence in FreeBASIC and main() initialization, calling Command within a global constructor (module constructor or UDT constructor called for static/shared object) is not safe (may even induce a runtime error).
Disabling filename globbing under Win32
Syntax
Usage
result = Command[$]( [ index ] )
Parameters
index
Zero-based index for a particular command-line argument.
Return Value
Returns the command-line arguments(s).
Description
Command returns command-line arguments passed to the program upon execution.
If index is less than zero (< 0), a space-separated list of all command-line arguments is returned, otherwise, a single argument is returned. A value of zero (0) returns the name of the executable; and values of one (1) and greater return each command-line argument.
If index is greater than the number of arguments passed to the program, the null string ("") is returned.
When the command line is parsed for arguments, everything between double quotes in the parameter list will be considered as a single parameter, and is returned with the double quotes.
By default, filename globbing for arguments (expansion of wildcards to filenames) is used on all ports of FreeBASIC for compatibility. Arguments on the command line containing wildcards are typically not expanded if when no file is matched or if properly quoted. Other special characters for redirection are typically not returned unless properly quoted. Consult the documentation on the shell being used for more information on the proper quoting of command line arguments.
WARNING: By nature of constructor precedence in FreeBASIC and main() initialization, calling Command within a global constructor (module constructor or UDT constructor called for static/shared object) is not safe (may even induce a runtime error).
Disabling filename globbing under Win32
Define the following global variable(s) somewhere in the source:
Disabling filename globbing under Dos
'' For MinGW.org and Cygwin runtimes:
Extern _CRT_glob Alias "_CRT_glob" As Long
Dim Shared _CRT_glob As Long = 0
'' For MinGW-w64 runtime:
Extern _dowildcard Alias "_dowildcard" As Long
Dim Shared _dowildcard As Long = 0
Extern _CRT_glob Alias "_CRT_glob" As Long
Dim Shared _CRT_glob As Long = 0
'' For MinGW-w64 runtime:
Extern _dowildcard Alias "_dowildcard" As Long
Dim Shared _dowildcard As Long = 0
Define the following function somewhere in the source:
Disabling filename globbing under Linux
Function __crt0_glob_function Alias "__crt0_glob_function" ( ByVal arg As UByte Ptr ) As UByte Ptr Ptr
Return 0
End Function
Return 0
End Function
Filename globbing is handled by the command shell. Quote the argument containing wildcards or disable filename globbing in the shell prior to executing the command. For example in bash use 'set -f' to disable wildcard expansion
Example
Print "program launched via: " & Command(0)
Dim As Integer i = 1
Do
Dim As String arg = Command(i)
If Len(arg) = 0 Then
Exit Do
End If
Print "command line argument " & i & " = """ & arg & """"
i += 1
Loop
If i = 1 Then
Print "(no command line arguments)"
End If
Sleep
Dim As Integer i = 1
Do
Dim As String arg = Command(i)
If Len(arg) = 0 Then
Exit Do
End If
Print "command line argument " & i & " = """ & arg & """"
i += 1
Loop
If i = 1 Then
Print "(no command line arguments)"
End If
Sleep
Dialect Differences
- The string type suffix $ is obligatory in the -lang qb dialect.
- The string type suffix $ is optional in the -lang fblite and -lang fb dialects.
Differences from QB
- The numeric argument was not supported in QB.
- QB converted the parameter list to uppercase before returning it, FreeBASIC doesn't.
- By default arguments containing wildcard characters are expanded (filename globbing)
See also