$ cat >> fakepager.py < import sys > for line in sys.stdin: > sys.stdout.write('paged! %r\n' % line) > EOF Enable ui.formatted because pager won't fire without it, and set up pager and tell it to use our fake pager that lets us see when the pager was running. $ cat >> $HGRCPATH < [ui] > formatted = yes > [pager] > pager = python $TESTTMP/fakepager.py > EOF $ hg init repo $ cd repo $ echo a >> a $ hg add a $ hg ci -m 'add a' $ for x in `python $TESTDIR/seq.py 1 10`; do > echo a $x >> a > hg ci -m "modify a $x" > done By default diff and log are paged, but id is not: $ hg diff -c 2 --pager=yes paged! 'diff -r f4be7687d414 -r bce265549556 a\n' paged! '--- a/a\tThu Jan 01 00:00:00 1970 +0000\n' paged! '+++ b/a\tThu Jan 01 00:00:00 1970 +0000\n' paged! '@@ -1,2 +1,3 @@\n' paged! ' a\n' paged! ' a 1\n' paged! '+a 2\n' $ hg log --limit 2 paged! 'changeset: 10:46106edeeb38\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! 'changeset: 9:6dd8ea7dd621\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' $ hg id 46106edeeb38 tip We can enable the pager on id: BROKEN: should be paged $ hg --config pager.attend-id=yes id 46106edeeb38 tip Setting attend-$COMMAND to a false value works, even with pager in core: $ hg --config pager.attend-diff=no diff -c 2 diff -r f4be7687d414 -r bce265549556 a --- a/a Thu Jan 01 00:00:00 1970 +0000 +++ b/a Thu Jan 01 00:00:00 1970 +0000 @@ -1,2 +1,3 @@ a a 1 +a 2 If 'log' is in attend, then 'history' should also be paged: $ hg history --limit 2 --config pager.attend=log paged! 'changeset: 10:46106edeeb38\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! 'changeset: 9:6dd8ea7dd621\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' Pager should not start if stdout is not a tty. $ hg log -l1 -q --config ui.formatted=False 10:46106edeeb38 Pager should be disabled if pager.pager is empty (otherwise the output would be silently lost.) $ hg log -l1 -q --config pager.pager= 10:46106edeeb38 Pager with color enabled allows colors to come through by default, even though stdout is no longer a tty. $ cat >> $HGRCPATH < [extensions] > color= > [color] > mode = ansi > EOF $ hg log --limit 3 paged! '\x1b[0;33mchangeset: 10:46106edeeb38\x1b[0m\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! '\x1b[0;33mchangeset: 9:6dd8ea7dd621\x1b[0m\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' paged! '\x1b[0;33mchangeset: 8:cff05a6312fe\x1b[0m\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 8\n' paged! '\n' An invalid pager command name is reported sensibly if we don't have to use shell=True in the subprocess call: $ hg log --limit 3 --config pager.pager=this-command-better-never-exist missing pager command 'this-command-better-never-exist', skipping pager \x1b[0;33mchangeset: 10:46106edeeb38\x1b[0m (esc) tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: modify a 10 \x1b[0;33mchangeset: 9:6dd8ea7dd621\x1b[0m (esc) user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: modify a 9 \x1b[0;33mchangeset: 8:cff05a6312fe\x1b[0m (esc) user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: modify a 8 A complicated pager command gets worse behavior. Bonus points if you can improve this. $ hg log --limit 3 \ > --config pager.pager='this-command-better-never-exist --seriously' \ > 2>/dev/null || true Pager works with shell aliases. $ cat >> $HGRCPATH < [alias] > echoa = !echo a > EOF $ hg echoa a BROKEN: should be paged $ hg --config pager.attend-echoa=yes echoa a Pager works with hg aliases including environment variables. $ cat >> $HGRCPATH <<'EOF' > [alias] > printa = log -T "$A\n" -r 0 > EOF $ A=1 hg --config pager.attend-printa=yes printa paged! '1\n' $ A=2 hg --config pager.attend-printa=yes printa paged! '2\n' Something that's explicitly attended is still not paginated if the pager is globally set to off using a flag: $ A=2 hg --config pager.attend-printa=yes printa --pager=no 2 Pager should not override the exit code of other commands $ cat >> $TESTTMP/fortytwo.py <<'EOF' > from mercurial import cmdutil, commands > cmdtable = {} > command = cmdutil.command(cmdtable) > @command('fortytwo', [], 'fortytwo', norepo=True) > def fortytwo(ui, *opts): > ui.write('42\n') > return 42 > EOF $ cat >> $HGRCPATH <<'EOF' > [extensions] > fortytwo = $TESTTMP/fortytwo.py > EOF $ hg fortytwo --pager=on paged! '42\n' [42] A command that asks for paging using ui.pager() directly works: $ hg blame a paged! ' 0: a\n' paged! ' 1: a 1\n' paged! ' 2: a 2\n' paged! ' 3: a 3\n' paged! ' 4: a 4\n' paged! ' 5: a 5\n' paged! ' 6: a 6\n' paged! ' 7: a 7\n' paged! ' 8: a 8\n' paged! ' 9: a 9\n' paged! '10: a 10\n' but not with HGPLAIN $ HGPLAIN=1 hg blame a 0: a 1: a 1 2: a 2 3: a 3 4: a 4 5: a 5 6: a 6 7: a 7 8: a 8 9: a 9 10: a 10 explicit flags work too: $ hg blame --pager=no a 0: a 1: a 1 2: a 2 3: a 3 4: a 4 5: a 5 6: a 6 7: a 7 8: a 8 9: a 9 10: a 10 Put annotate in the ignore list for pager: $ cat >> $HGRCPATH < [pager] > ignore = annotate > EOF $ hg blame a 0: a 1: a 1 2: a 2 3: a 3 4: a 4 5: a 5 6: a 6 7: a 7 8: a 8 9: a 9 10: a 10 Environment variables like LESS and LV are set automatically: $ cat > $TESTTMP/printlesslv.py < import os, sys > sys.stdin.read() > for name in ['LESS', 'LV']: > sys.stdout.write(('%s=%s\n') % (name, os.environ.get(name, '-'))) > sys.stdout.flush() > EOF $ cat >> $HGRCPATH < [alias] > noop = log -r 0 -T '' > [ui] > formatted=1 > [pager] > pager = $PYTHON $TESTTMP/printlesslv.py > EOF $ unset LESS $ unset LV $ hg noop --pager=on LESS=FRX LV=-c $ LESS=EFGH hg noop --pager=on LESS=EFGH LV=-c