hg export [OPTION]... [-o OUTFILESPEC] REV...

dump the header and diffs for one or more changesets

    Print the changeset header and diffs for one or more revisions.

    The information shown in the changeset header is: author, date, branch
    name (if non-default), changeset hash, parent(s) and commit comment.

    Note:
       export may generate unexpected diff output for merge changesets, as it
       will compare the merge changeset against its first parent only.

    Output may be to a file, in which case the name of the file is given using
    a format string. The formatting rules are as follows:

    "%%"          literal "%" character
    "%H"          changeset hash (40 hexadecimal digits)
    "%N"          number of patches being generated
    "%R"          changeset revision number
    "%b"          basename of the exporting repository
    "%h"          short-form changeset hash (12 hexadecimal digits)
    "%m"          first line of the commit message (only alphanumeric
                  characters)
    "%n"          zero-padded sequence number, starting at 1
    "%r"          zero-padded changeset revision number

    Without the -a/--text option, export will avoid generating diffs of files
    it detects as binary. With -a, export will generate a diff anyway,
    probably with undesirable results.

    Use the -g/--git option to generate diffs in the git extended diff format.
    See "hg help diffs" for more information.

    With the --switch-parent option, the diff will be against the second
    parent. It can be useful to review a merge.

    Returns 0 on success.

options:

 -o --output FORMAT print output to file with formatted name
    --switch-parent diff against the second parent
 -r --rev REV [+]   revisions to export
 -a --text          treat all files as text
 -g --git           use git extended diff format
    --nodates       omit dates from diff headers

[+] marked option can be specified multiple times

use "hg -v help export" to show more info