# comby > Tool for structural code search and replace that supports many languages. > More information: . - Match and rewrite templates, and print changes: `comby '{{assert_eq!(:[a], :[b])}}' '{{assert_eq!(:[b], :[a])}}' {{.rs}}` - Match and rewrite with rewrite properties: `comby '{{assert_eq!(:[a], :[b])}}' '{{assert_eq!(:[b].Capitalize, :[a])}}' {{.rs}}` - Match and rewrite in-place: `comby -in-place '{{match_pattern}}' '{{rewrite_pattern}}'` - Only perform matching and print matches: `comby -match-only '{{match_pattern}}' ""`