sqitchchanges(3)

Name
sqitchchanges - Specifying changes for Sqitch

Description
Many Sqitch commands take change parameters as arguments. Depending on the command, they denote a specific change or, for commands which walk change history or the change plan (such as "sqitch log"), all changes which can be reached from that change. Most commands search the plan for the relevant change, though some, such as "sqitch revert" and "sqitch log", search the database for the change.

  Change Names
A change name, such as that passed to "sqitch add" and written to the plan file, has a few limitations on the characters it may contain. The rules are:

•   Must be at least one character.

•   Must contain no blank characters.

•   The first character may not be punctuation.

•   Last letter may not be punctuation.

•   Must not end in "~", "^", "/", "=", or "%" followed by digits.

•   All other characters may be any UTF-8 character other than ":", "@", "#", and "\".

Note that "_" (underscore) is never considered punctuation. Some examples of valid names:

"foo"
12
"t"
6
"阱阪阬"
"阱阪阬92"
"foo/bar"
"beta1"
"foo_"
"_foo"
"v1.0-1b"
"v1.2-1"
"v1.2+1"
"v1.2_1"

Some examples of invalid names:

"^foo"
"foo^"
"foo^6"
"foo^666"
%hi
"hi!"
"foo@bar"
"foo:bar"
"foo\bar"
"+foo"
"-foo"
@foo

  Tag Names
A tag name, such as that passed to "sqitch tag" and written to the plan file, adhere by the same rules as "Change Names" with one additional limitation: tags must not contain a slash character ("/"). Example valid change name but invalid tag name:

"foo/bar"

Specifying Changes
A change parameter names a change object. It uses what is called an extended SHA1 syntax. Here are various ways to spell change names:

"<change_name>", e.g., "users_table"
    The name of a change itself, as it was added to the plan via "sqitch add".

"@<tag_name>", e.g., @rc1
    The change as of the named tag. Tags can be added to the plan via "sqitch tag".

"<change_name>@<tag_name>", e.g., "users_table@beta1"
    The named change as of a tag, also known as a tag-qualified change name. For change iteration commands (such as "sqitch log"), this means the instance of a change with that name before the specified tag. For dependency parameters (such as in "sqitch add"), this means any instance of a change just before that tag, or at any time after the tag.

"<sha1>", e.g., "40763784148fa190d75bad036730ef44d1c2eac6"
    The change full SHA1 ID (40-byte hexadecimal string). In some cases, such as "sqitch add", the ID may refer to a change in another Sqitch project.

"<project>:<change_name>", e.g., "mybase:users_table"
    The name of a change in a specific project. Non-SHA1 change parameters without a project prefix are assumed to belong to the current project. Most useful for declaring a dependency on a change from another project in "sqitch add".

"<project>:@<tag_name>", e.g., "mybase:@rc1"
    The name of a tag in an the named project.

"<project>:<change_name>@<tag_name>", e.g., "project:users_table@beta1"
    A tag-qualified named change in the named project.

"<project>:<sha1>", e.g., "mybase:40763784148fa190d75bad036730ef44d1c2eac6"
    The full SHA1 ID from another project. Probably redundant, since the SHA1 I should itself be sufficient. But useful for declaring dependencies in the current project so that "sqitch add" or "sqitch rework" will validate that the specified change is in the current project.

@HEAD
"HEAD"
    Special symbolic name for the last change in the plan.

@ROOT
"ROOT"
    Special symbolic name for the first change in the plan.

"<change>^", e.g., "@HEAD^^", "@HEAD^3", "@beta^2"
    A suffix "^" to a symbolic or actual name means the change prior to that change. Two "^"s indicate the second prior change. Additional prior changes can be specified as "^<n>", where "<n>" represents the number of changes to go back.

"<change>~", e.g., "@ROOT~", "@ROOT~~", "@bar~4"
    A suffix "~" to a symbolic or actual name means the change after that change. Two "~"s indicate the second following change. Additional following changes can be specified as "~<n>", where "<n>" represents the number of changes to go forward.

Sqitch
Part of the sqitch suite.