chat: add page (#13713)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>
Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/linux/chat.md

@@ -0,0 +1,33 @@
+# chat
+
+> Automate conversations with a modem or serial device.
+> Commonly used to establish PPP (Point-to-Point Protocol) connections.
+> More information: <https://manned.org/chat.8>.
+
+- Execute a chat script directly from the command line:
+
+`chat '{{expect_send_pairs}}'`
+
+- Execute a chat script from a file:
+
+`chat -f '{{path/to/chat_script}}'`
+
+- Set a custom timeout (in seconds) for expecting a response:
+
+`chat -t {{timeout_in_seconds}} '{{expect_send_pairs}}'`
+
+- Enable verbose output to log the conversation to `syslog`:
+
+`chat -v '{{expect_send_pairs}}'`
+
+- Use a report file to log specific strings received during the conversation:
+
+`chat -r {{path/to/report_file}} '{{expect_send_pairs}}'`
+
+- Dial a phone number using a variable, substituting `\T` in the script:
+
+`chat -T '{{phone_number}}' '{{"ATDT\\T CONNECT"}}'`
+
+- Include an abort condition if a specific string is received:
+
+`chat 'ABORT "{{error_string}}" {{expect_send_pairs}}'`