We can hide specific texts in device config files by replacing them with "********".
Format of Settings
Specify your settings with a multi-line text. Each line must look like:
| mode_selection | part_a | | | part_b | | | part_c | \r\n |
.
- mode_selection: one of "exact_prefix:" (note the colon), "regex_replacement:" and "" (empty string). You use this field to select the mode of text processing between exact_prefix and regex_replacement; if you use an empty string "", the mode defaults to exact_prefix.
- part_a: a list of device type ID's represented by int32_t in CSV format. No "|", "\r" or "\n" characters are allowed.
- |: a vertical bar character "|".
- part_b: a string that will be prepended to each replaced line in a device config files. No "|", "\r" or "\n" characters are allowed.
- |: another vertical bar character "|".
- part_c: a list of fields in CSV format about the details of how lines in device config files should be replaced. No "\r" or "\n" characters are allowed.
- \r\n: a carriage return character and a newline character.
- For each mode, a given device type ID should NOT appear more than once. If it does, the last appearance takes effect.
- If a line of settings has a bad format, the whole line will be ignored.
How It Works
exact_prefix Mode
You should provide a list of keywords in part_c. For each line in a device config file, all leading blank characters (that is, tab '\t' and space ' ') are skipped. Then if the remaining starts with one of the provided keywords (use key to denote this keyword), a replacement will take place. The whole line will become:
| leading blank characters | part_b | key | ******** |
If a keyword is a prefix of another, the shorter takes effect in the replacement.
Example
Given the following line of settings:
exact_prefix:2008,4020|###|set admin user blah,set admin user
if a device 4020 has the following line in its config file,
set admin user blah abcdef890
the line will be substituted with
###set admin user ********
regex_replacement Mode
You should provide a list of Perl regular expressions in part_c. In order to replace a line in the config file using a regex, the regex must match the whole config line without "\r\n". In the regex, use parenthesis-enclosed capture groups "(...)" to specify the parts of the config line that you would like to erase in the outcome. Those capture groups will be replaced with " ******** ". In addition, nested parentheses are ignored.
Example
Given the following line of settings,
regex_replacement:2008,4020|!@#|"set admin user(.*)set admin pass(.*) OK",set admin user(.*)set admin pass((.*) OK).+
if a device 2008 has the following line in its config file,
set admin user username; set admin pass PASSWORD OK; and something more
the line will be substituted with
!@#set admin user ******** set admin pass ******** ; and something more
Order of Processing
- exact_prefix mode is evaluated first. For any line the in the config file, if it's successfully replaced under the rule of exact_prefix, the processing of this line is considered done. Even if there is a regex that matches the line well, it will not be considered.
- Regular expressions in the regex list are considered in the order of their appearances in the settings. If a regex successfully matches, all remaining regexes are ignored for this line.
Performance
- The exact_prefix mode works fast. For any given config line, the time complexity of processing it is O(length of the longest keyword).
- Use regex_replacement mode sparingly.
