Method _send_output_to_pager

awscli/help.py:199–222

(self, output)

    PAGER = 'less -R'

    def _send_output_to_pager(self, output):
        cmdline = self.get_pager_cmdline()
        if not self._exists_on_path(cmdline[0]):
            LOG.debug(
                f"Pager '{cmdline[0]}' not found in PATH, printing raw help."
            )
            self.output_stream.write(output.decode('utf-8') + "\n")
            self.output_stream.flush()
            return
        LOG.debug("Running command: %s", cmdline)
        with ignore_ctrl_c():
            # We can't rely on the KeyboardInterrupt from
            # the CLIDriver being caught because when we
            # send the output to a pager it will use various
            # control characters that need to be cleaned
            # up gracefully.  Otherwise if we simply catch
            # the Ctrl-C and exit, it will likely leave the
            # users terminals in a bad state and they'll need
            # to manually run ``reset`` to fix this issue.
            # Ignoring Ctrl-C solves this issue.  It's also
            # the default behavior of less (you can't ctrl-c
            # out of a manpage).
            p = self._popen(cmdline, stdin=PIPE)
            p.communicate(input=output)

    def _exists_on_path(self, name):
        # Since we're only dealing with POSIX systems, we can