Expect Scripts

Expect scripts define series of commands that can be sent to devices and expected device replies that control script behavior. To execute an Expect script, Iotellect Server connects to a device using Telnet or SSH protocol.

Expect scripts are divided into three groups:

• Read Configuration Scripts. Those scripts are called only from device configuration backup sequences.

• Write Configuration Scripts.Those scripts are called only from device configuration restoration sequences.

• Configuration Scripts. These are generic purpose scripts used for changing device configuration or controlling devices.

The scripts are managed via global configuration settings of the Network Host device driver.

Each Expect script is configured as a table. A record in this table defines a command to be sent to a device and expected device output.

Each script record contains:

• Expect. This is an Iotellect Expression that should result in a string. This string will be treated as a regular expression that device output should match. The regular expression is "wrapped" into an Iotellect Expression to allow dynamic construction of regular expression that depends on environment.

To put a static regular expression into Expect field, just single-quote or double quote it and escape all quotes and backslashes inside the expression itself.

Example: "(?s).*\s*(([Uu]sername: )|([Ll]ogin.*: ))\z" This Expect field value will result in the following regular expression: (?s).*s*(([Uu]sername: )|([Ll]ogin.*: ))z The regular expression will, in its turn, match Login: or Username: prompts sent by the device. Thus, this Expect field is suitable to wait for device's username prompt.

• Send. This is an Iotellect Expression that should result in a string. This string will be sent to a device when text matching Expect field value is received from a device.

Example: {username} This Send field value will resolve to username defined in per-device configuration backup or restore settings.

Example: 'enable' This Send field value will cause sending enable command to the device.

Example: 'show ' + {env/configurationType} + '-config' This Send field value refers configurationType environment variable that was defined by previously executed rules of configuration backup/restore sequence that has called this Expect script.

• Error Expect. Similarly to Expect field, this is an Iotellect Expression that should result in a string. This string will be treated as a regular expression that device output should match. If this happens, device reply is deemed an error and Expect script execution fails with an error message defined by Error Message field.

• Error Message. This is an Iotellect Expression that should result in a string. This string will be returned as an error message if device output will match regular expression defined by Error Expect field.

• Output. This is an Iotellect Expression that should result in a string representing a name of an environment variable. Any output produced by the device in response to Send command will be written into this variable.

Example: 'configuration' This expression will resolve to a configuration string. Therefore, device reaction to Send command will be written into configuration environment variable.

• Output Filter. This is an Iotellect Expression that should result in a string. This string will be treated as a regular expression. Any string matching this expression will be deleted from device's output received in response to Send command before this output is written to Output variable.

Example: "(Building)|(Current)|(Using)|(show)" This Output Filter field value will resolve to (Building)|(Current)|(Using)|(show)regular expression. Thus, words Building, Current, Using, and Show will be removed from device output before it will be put to Output variable.

• Comment. Any hint describing the purpose of an Expect script line.

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