Exec

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Exec

Runs a program by its path with arguments, waits, and returns its exit code or -1.

Syntax

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

Parameters

• program
• arguments

Description

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

Return Value

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

Remarks

Usage

result = Exec( program, arguments )

Platform Differences

• On Windows program is not searched for on the PATH: Exec( "cmd.exe", "/c dir" ) returns -1. Give the full path -- for the command interpreter, Environ( "COMSPEC" ). On Linux and macOS a bare name is searched for on the PATH.
• Linux requires the program case matches the real name of the file. Windows, DOS and a default macOS volume are case insensitive. The program being executed may be case sensitive for its command line parameters. Path separators in Linux and macOS 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

Examples

'A Windows based example but the same idea applies to Linux

Const exename = "NoSuchProgram.exe"

Const cmdline = "arg1 arg2 arg3"

Dim result As Long

result = Exec( exename, cmdline )

If result = -1 Then

    Print "Error running "; exename

Else

    Print "Exit code:"; result

End If

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Category: Operating System Functions
Kind: function

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Reproduced from the FreeBASIC Wiki Manual under the GNU Free Documentation License 1.3 — with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. Copyright © the FreeBASIC project and wiki contributors. See License.