Exec

FreeBASIC

Exec
 
Temporarily transfers execution to an external program

Syntax

Declare Function Exec ( ByRef program As Const String, ByRef arguments As Const String ) As Long

Usage

result = Exec( program, arguments )

Parameters

program
The file name (including file path) of the program (executable) to transfer control to.
arguments
The command-line arguments to be passed to the program.

Return Value

The exit status of the program, or negative one (-1) if the program could not be executed.

Description

Transfers control over to an external program. When the program exits, execution resumes immediately after the call to Exec.

Example

'A Windows based example but the same idea applies to Linux
Const exename = "NoSuchProgram.exe"
Const cmdline = "arg1 arg2 arg3"
Dim result As Integer
result = Exec( exename, cmdline )
If result = -1 Then
    Print "Error running "; exename
Else
    Print "Exit code:"; result
End If

Platform Differences

  • Linux requires the program case matches the real name of the file. Windows and DOS are case insensitive. The program being executed may be case sensitive for its command line parameters.
  • Path separators in Linux are forward slashes / . Windows uses backward slashes \ but it allows for forward slashes . DOS uses backward \ slashes.
  • Exit code is limited to 8 bits in DOS.

Dialect Differences

  • Not available in the -lang qb dialect unless referenced with the alias __Exec.

Differences from QB

  • New to FreeBASIC

See also

  • Chain transfer temporarily, without arguments
  • Run one-way transfer
  • Command pick arguments