#05AB1E (legacy), 1 byte

Any single byte in 05AB1E (legacy) would work, except for [ (infinite loop).

See here all possible outputs for all possible single-byte 05AB1E programs.

Removing that single byte so an empty program remains will output the content of info.txt to STDOUT instead by default.

Try it online.

#05AB1E , 1 byte

?

Try it online.

Unfortunately an empty program in the new version of 05AB1E only outputs a 1-byte newline by default (Try it online), so almost none of the 1-byte characters are possible since they'll have to output nothing. The only possible program that outputs nothing (so also not the implicit newline) is ? as far as I know.

05AB1E (legacy), 1 byte

Any single byte in 05AB1E (legacy) would work, except for [ (infinite loop).

See here all possible outputs for all possible single-byte 05AB1E programs.

Removing that single byte so an empty program remains will output the content of info.txt to STDOUT instead by default.

Try it online.

05AB1E , 1 byte

?

Try it online.

Unfortunately an empty program in the new version of 05AB1E only outputs a 1-byte newline by default (Try it online), so almost none of the 1-byte characters are possible since they'll have to output nothing. The only possible program that outputs nothing (so also not the implicit newline) is ? as far as I know.