Special Variables

The following variables have special meaning to the Expect program.

spawn_id

Spawn descriptor for the current spawned process (can be set).

user_spawn_id

Spawn descriptor for user input.

tty_spawn_id

Spawn descriptor for /dev/tty.

any_spawn_id

Used in expect command to match input on any active spawn descriptor.

error_spawn_id

Spawn descriptor for standard error output.

argv

List containing the command-line arguments.

argc

The number of elements in argv.

argv0

The name of the script or program being run.

exp_exec_library

Directory containing architecture-dependent library files.

exp_library

Directory containing architecture-independent library files.

expect_out

Array containing output strings collected by the expect command (see the description of expect, later in this chapter).

expect_out(buffer)

Matching any previously unmatched output.

expect_out(n, string)

Substring that matched regular expression n, where n is 1 through 9.

expect_out(0, string)

String that matched entire pattern.

expect_out(n, start)

Starting index in buffer of regular expression n.

expect_out(n, end)

Ending index in buffer of regular expression n.

expect_out(spawn_id)

Spawn ID associated with matching output.

spawn_out(slave, name)

Name of the pty slave device.

interact_out

Array containing output strings collected by interact command, in the same format as expect_out.

send_human

Controls behavior of send with the -h option. A list of five numeric elements: (1) interarrival time of characters, (2) interarrival time of word endings, ...

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