pretty: support padding placeholders, %< %> and %><

Either %<, %> or %>< standing before a placeholder specifies how many
columns (at least as the placeholder can exceed it) it takes. Each
differs on how spaces are padded:

  %< pads on the right (aka left alignment)
  %> pads on the left (aka right alignment)
  %>< pads both ways equally (aka centered)

The (<N>) follows them, e.g. `%<(100)', to specify the number of
columns the next placeholder takes.

However, if '|' stands before (<N>), e.g. `%>|(100)', then the number
of columns is calculated so that it reaches the Nth column on screen.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index bad627a93..e2345d229 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -164,6 +164,14 @@ The placeholders are:
 - '%x00': print a byte from a hex code
 - '%w([<w>[,<i1>[,<i2>]]])': switch line wrapping, like the -w option of
   linkgit:git-shortlog[1].
+- '%<(<N>)': make the next placeholder take at least N columns,
+  padding spaces on the right if necessary
+- '%<|(<N>)': make the next placeholder take at least until Nth
+  columns, padding spaces on the right if necessary
+- '%>(<N>)', '%>|(<N>)': similar to '%<(<N>)', '%<|(<N>)'
+  respectively, but padding spaces on the left
+- '%><(<N>)', '%><|(<N>)': similar to '%<(<N>)', '%<|(<N>)'
+  respectively, but padding both sides (i.e. the text is centered)
 
 NOTE: Some placeholders may depend on other options given to the
 revision traversal engine. For example, the `%g*` reflog options will