The syslog-ng 3.0 Administrator Guide

When writing the names of options and parameters (or other reserved words), the hyphen (-) and underscore (_) characters are equivalent, e.g., max-connections(10) and max_connections(10) are both correct.

Number can be prefixed with + or - to indicate positive or negative values. Numbers beginning with zero (0) or 0x are treated as octal or hexadecimal numbers, respectively.

You can use commas (,) to separate options or other parameters for readability; syslog-ng completely ignores them. The following declarations are equivalent:

source s_demo_stream { 
                        unix-stream("/dev/log" max-connections(10) group(log)); };

source s_demo_stream { 
                        unix-stream("/dev/log", max-connections(10), group(log)); };

Strings between single quotes ('string') are treated literally, you do not have to escape special characters. This makes writing and reading regular expressions much more simple: it is recommended to use single quotes when writing regular expressions.

When enclosing strings between double-quotes ("string"), you have to escape special characters: e.g., when enclosing a regular expression that uses the \ character to escape a special character, you have to add an extra \ (e.g., "\\n"). It is recommended to use single quotes instead.

Enclosing normal strings between double-quotes ("string") is not necessary, you can just omit the double-quotes. E.g., when writing filters, match("sometext") and match(sometext) will both match for the sometext string.

When enclosing object IDs (e.g., the name of a destination) between double-quotes ("mydestination"), the ID can include whitespace as well, e.g.:

source "s demo stream" { 
                        unix-stream("/dev/log" max-connections(10) group(log)); };