Added persist-tool to manual pages.

Signed-off-by: Zsolt Gyulai (zgyulai) <zsolt.gyulai@quest.com>

Author: zsoltgyulai94

doc/_admin-guide/190_The_syslog-ng_manual_pages/011_persist-tool.md

@@ -0,0 +1,98 @@
+---
+title: The persist-tool manual page
+id: adm-man-persist-tool
+description: >-
+    persist-tool --- {{ site.product.short_name }} configuration file
+---
+
+## Synopsis
+
+persist-tool [command] [options]
+
+## Description
+
+This manual page is only an abstract.
+
+The persist-tool application is a utility that can be used to dump the content of the persist file, and manipulate its content.
+
+![]({{ site.baseurl}}/assets/images/caution.png)
+**CAUTION:** Persist-tool is a special tool for syslog-ng experts. Do use the tool unless you know exactly what you are doing. Misconfiguring it will result in irrecoverable damage to the persist file, without any warning.
+{: .notice--danger}
+
+**NOTE:** 
+Limitations:
+* The persist-state functions can be used only with `SLP4` or newer persist files. Older persist files are not supported.
+* Wildcard characters are not supported in file and directory names.
+
+{: .notice--info}
+
+## The dump command
+
+dump [options] [persist_file]
+
+Use the `dump` command to print the current content of the persist file in JSON format to the console.
+
+The `dump` command has the following options:
+* `--help` or `-?`
+Display a brief help message.
+
+### Example: persist-tool dump
+
+```config
+persist-tool dump /opt/syslog-ng/var/syslog-ng.persist
+```
+
+A valid output is the following:
+
+```config
+run_id = { "value": "00 00 00 00 0C 00 00 00 " }
+host_id = { "value": "00 00 00 00 5F 49 2F 01 " }
+```
+
+## The add command
+
+add [options] [input_file] 
+
+Use the `add` command to add or modify a specified state-entry in the persist file. The state-entry should be in the same format as the `dump` command displays it. If the given state-entry already exists, it will be updated. Otherwise, a new value will be added. If the given persist state is invalid, it will be skipped.
+
+To use the `add` command: use `persist-tool dump` to print the content of the current persist file, and redirect it to a file. Edit the content of this file. Use `persist-tool` add with this file to modify the persist.
+
+The `add` command has the following options:
+* `--help` or `-?`
+Display a brief help message.
+* `--output-dir=<directory>` or `-o`
+Required parameter. The directory where the persist file is located at. The name of the persist file stored in this directory must be syslog-ng.persist.
+* `--persist-name=<filename>` or `-p`
+Optional parameter. The name of the persist file to generate. Default value: syslog-ng.persist.
+
+### Example: add dump_persist
+
+```config
+/opt/syslog-ng/bin/persist-tool add dump_persist -o .
+```
+
+A valid output is the following:
+
+```config
+log_reader_curpos(Application)      OK
+affile_sd_curpos(/var/aaa.txt)        OK
+```
+
+An invalid output is the following:
+
+```config
+log_reader_curpos(Application)      OK
+wrong
+FAILED (error: Invalid entry syntax)
+affile_sd_curpos(/var/aaa.txt)        OK
+```
+
+## Files
+
+/opt/syslog-ng/bin/persist-tool
+
+## See also
+
+The syslog-ng.conf manual page
+
+The syslog-ng manual page