Handling Inline Comments in INI Files

Inline Comments in INI

Unlike full-line comments, inline comments appear at the end of a key-value line, separated by whitespace followed by ; or #. The converter strips these from the value during parsing.

Example INI

[server]
host=0.0.0.0          ; listen on all interfaces
port=8443              # HTTPS port
workers=4              ; one per CPU core
timeout=30             ; seconds
bind_address=127.0.0.1 ; loopback only in dev

[paths]
; Full-line comment preserved as-is
data="/var/lib/app;data"  ; semicolon inside quotes is NOT a comment
cache_dir=/tmp/cache      # cleared on reboot

Generated JSON

{
  "server": {
    "host": "0.0.0.0",
    "port": 8443,
    "workers": 4,
    "timeout": 30,
    "bind_address": "127.0.0.1"
  },
  "paths": {
    "data": "/var/lib/app;data",
    "cache_dir": "/tmp/cache"
  }
}

Parsing Rules for Inline Comments

1. The parser looks for whitespace followed by ; or # in the unquoted portion of the value
2. Everything from the comment marker to the end of the line is stripped
3. Semicolons or hashes inside quoted values are not treated as comments
4. The value is then trimmed of any trailing whitespace left by the removal

Edge Cases

INI line	Parsed value	Notes
key=value ; comment	"value"	Standard inline comment
key="val;ue" ; comment	"val;ue"	Quoted semicolons preserved
key=value;no_space	"value;no_space"	No space before ; — not a comment
key= ; comment	""	Empty value with comment

Difference from Full-Line Comments

Full-line comments (lines starting with ; or #) can optionally be preserved in JSON. Inline comments are always stripped during conversion because there is no standard way to associate them with a specific key in JSON.