Cannot use / to search when piped.

[dkowis]

This tool is glorious!

But, I found a problem. If you pipe info to it, say from an aws cli: aws iam list-instance-profiles | jless for example, I cannot search.

Hitting / immediately exits, which was surprising.

[PaulJuliusMartinez]

Thank you!

I'm able to reproduce the issue. Looks like it might be an issue with the readline library I'm using, so it might take some time to figure out.

[alimoezzi]

I also faced this bug when piping the output

[n1000]

I ran into this also. From strace it looks like the readline implementation is attempting to read the "/" from fd=0, which is connected to the file being piped as input, not the TTY, and hitting the EOF (since the file has already been fully read):

poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}], 2, -1) = 1 ([{fd=3, revents=POLLIN}])
// the read below on fd 3 looks like a read on sigwinch_pipe by TuiInput
read(3, "/", 1024)                      = 1
write(1, "\33[?25h\33[65;1H\33[0m", 17) = 17
// oops? I think this is a read by rustyline readline_with() (on stdin/the file instead of a terminal connected fd):
read(0, "", 8192)                       = 0
write(1, "\33[?25l\33[65;1H\33[0m\33[2K", 21) = 21
write(2, "thread '", 8thread ')                 = 8
write(2, "main", 4main)                     = 4
write(2, "' panicked at '", 15' panicked at ')         = 15
write(2, "called `Result::unwrap()` on an `Err` value: Eof", 48called `Result::unwrap()` on an `Err` value: Eof) = 48
write(2, "', ", 3', )                      = 3
write(2, "/home/nathan/.cargo/registry/src/github.com-1ecc6299db9ec823/jless-0.7.1/src/app.rs", 83/home/nathan/.cargo/registry/src/github.com-1ecc6299db9ec823/jless-0.7.1/src/app.rs) = 83

I think the rustyline function below might need to support operating on a specific file descriptor (instead of using io::stdin(), which in this case is no longer connected to the terminal):

    fn readline_with(&mut self, prompt: &str, initial: Option<(&str, &str)>) -> Result<String> {
        if self.term.is_unsupported() {
            debug!(target: "rustyline", "unsupported terminal");
            // Write prompt and flush it to stdout
            let mut stdout = io::stdout();
            stdout.write_all(prompt.as_bytes())?;
            stdout.flush()?;

            readline_direct(io::stdin().lock(), io::stderr(), &self.helper)
        } else if self.term.is_stdin_tty() {
            readline_raw(prompt, initial, self)
        } else {
            debug!(target: "rustyline", "stdin is not a tty");
            // Not a tty: read from file / pipe.
            readline_direct(io::stdin().lock(), io::stderr(), &self.helper)
        }
    }

[jli]

Here's a workaround that doesn't create an intermediate file:

# crashes if you search
curl https://httpbin.org/get | jless

# search works!
jless <(curl https://httpbin.org/get)

[PaulJuliusMartinez]

This issue has been fixed and is available in the v0.7.2 release.