/usr/bin/runantlr is in antlr 2.7.7+dfsg-3.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 | #!/bin/sh
echo Running 'java antlr.Tool $*' with /usr/share/java/antlr.jar appended to the CLASSPATH variable
export CLASSPATH
CLASSPATH=$CLASSPATH:/usr/share/java/antlr.jar
java antlr.Tool $*
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