shell.pl -- Elementary shell commands

This library provides some basic (POSIX) shell commands defined in Prolog, such as pwd and ls for situations where there is no shell available or the shell output cannot be captured. Note that in recent versions (since 10.1.13) the GUI frontend swipl-win can capture process output on all supported platforms.

 shell

Execute an interactive shell. Uses shell_command/1 to find a suitable shell.

The shell's exit status is not our business, so shell/0 succeeds whatever it is. Note that if the shell cannot be executed shell/2 raises an exception.

 shell_command(-Shell:atom)

True when Shell is the preferred executable for running an interactive shell. Used by shell/0. The following options are tried to find a suitable shell command:

1. The Prolog flag shell
2. The environment variable %comspec% (Windows only)
3. The environment variable $SHELL
4. The Prolog flag posix_shell

Errors

- existence_error(config, shell) if no suitable shell can be found.

 cd

 cd(Dir)

Change working directory

 pushd

 pushd(+Dir)

 popd

 dirs

Manage the directory stack:

• pushd/1 is as cd/1, pushing th old directory on a stack
• pushd/0 swaps the current directory with the top of the stack
• popd/0 pops to the top of the stack
• dirs/0 lists the current directory and the stack.

 pwd

Print current working directory

 ls

 ls(+Pattern)

Listing similar to Unix ls -F, flagging directories with /. If the terminal supports it, Prolog source files are rendered as links using the OSC 8 escape sequence. When using Epilog, clicking a Prolog file opens it in the editor.

 mv(+From, +To) is det

Move (Rename) a file. If To is a directory, From is moved into the directory. Uses expand_file_name/2 on the From argument.

 rm(+File) is det

Remove (unlink) a file

 file_style(++File, =Style) is det[multifile]

True when File should be listed as a terminal hyperlink. The default only links Prolog source files.

Arguments:

Style

- is either url to make a hyperlink or a valid style argument for ansi_format/3.

 cls

CLear Screen. Emits ANSI control characters to clear the terminal.

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 ls(Arg1)

 cd(Arg1)

 pushd(Arg1)

 popd

 dirs