Stefan Sperling wrote: > Ben Reser wrote: >> I suspect we should allow the pager to be used with all our commands, >> though most of them should be disabled by default. I'd say the following >> should be enabled by default: >> blame >> cat >> diff >> list >> log >> mergeinfo (at least with --show-revs) >> proplist >> status > > I had a similar list. [...but...] > I would in fact be fine with having just 'help' use a pager by default. > > Some commands in your list could enable the pager only when acting > recursively, e.g. 'proplist -R', because recursive operation generally > implies more output. > > We could use a static list like the above, based on what cases > we believe will produce a lot of output.
I do like the idea of making the output more user-friendly by using a pager. But keep it simple. A pager by default just for help -- fine. A pager for all commands when producing more than a screenful of output -- fine. A static list of what commands we 'believe' will produce a lot of output -- no. The pager should not be used when stdout is not connected to a terminal, of course. > Or we could buffer up to one screenfull of data and decide to use the > pager based on whether the output is going to fill the entire screen. > This is more difficult to implement [...] Good behaviour, but don't implement it in Subversion, implement it in the pager! GNU 'less' already has this feature built in. If Windows/BSD/whatever doesn't have such a pager by default, the Subversion packager should provide one. In the extreme, I'd rather see us write one and ship it as a tool than build such functionality into 'svn' itself. >> A lot of these will make a lot more sense if we can reasonably default to >> something like the FRSX option set that git passes to less by default. For those without a copy of 'man less' in front of them: -F or --quit-if-one-screen Causes less to automatically exit if the entire file can be displayed on the first screen. -R or --RAW-CONTROL-CHARS Like -r, [Causes "raw" control characters to be displayed. The default is to display control characters using the caret notation] but only ANSI "color" escape sequences are output in "raw" form. Unlike -r, the screen appearance is maintained correctly in most cases. -S or --chop-long-lines Causes lines longer than the screen width to be chopped rather than folded. -X or --no-init Disables sending the termcap initialization and deinitialization strings to the terminal. This is sometimes desirable if the deinitialization string does something unnecessary, like clearing the screen. > less -F is causing issues for me, where I don't see any output at all if > the output doesn't fill screen. Not sure if this is specific to OpenBSD > or if it can also be seen on other systems. Do you see the same problem if you pipe the output from (non-patched) 'svn' straight into the same pager? Could it be related to '-X'? Could it be related to the sequence in which we close things: close the svn_cmdline_stream_for_stdout close the apr_stream_from_stdout close the pager flush stdout just before returning from main() See the 'flush' call in 'main()' -- wouldn't it make more sense to set up and tear down the pager there, rather than within each individual subcommand? - Julian
