New timestamp_format "human" with separators to increase human readability

ChangeLog

@@ -1,3 +1,6 @@
+unreleased
+* New timestamp_format "human" with separators to increase human readability
+
 btrbk-0.32.6
 
   * Fix backup of unrelated (by parent_uuid) snapshots (close #339).

btrbk

@@ -64,7 +64,7 @@ my $ipv4_addr_match = qr/(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}
 my $ipv6_addr_match = qr/[a-fA-F0-9]*:[a-fA-F0-9]*:[a-fA-F0-9:]+/; # simplified (contains at least two colons), matches "::1", "2001:db8::7"
 my $host_name_match = qr/(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])/;
 my $uuid_match = qr/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/;
-my $btrbk_timestamp_match = qr/(?<YYYY>[0-9]{4})(?<MM>[0-9]{2})(?<DD>[0-9]{2})(T(?<hh>[0-9]{2})(?<mm>[0-9]{2})((?<ss>[0-9]{2})(?<zz>(Z|[+-][0-9]{4})))?)?(_(?<NN>[0-9]+))?/;  # matches "YYYYMMDD[Thhmm[ss+0000]][_NN]"
+my $btrbk_timestamp_match = qr/(?<YYYY>[0-9]{4})-?(?<MM>[0-9]{2})-?(?<DD>[0-9]{2})_?(T?(?<hh>[0-9]{2})-?(?<mm>[0-9]{2})((?<ss>[0-9]{2})(?<zz>(Z|[+-][0-9]{4})))?)?(_(?<NN>[0-9]+))??/;  # matches "YYYYMMDD[Thhmm[ss+0000]][_NN]"
 my $raw_postfix_match = qr/\.btrfs(\.($compress_format_alt))?(\.(gpg|encrypted))?/;  # matches ".btrfs[.gz|.bz2|.xz|...][.gpg|.encrypted]"
 my $safe_file_match = qr/[0-9a-zA-Z_@\+\-\.\/]+/;  # note: ubuntu uses '@' in the subvolume layout: <https://help.ubuntu.com/community/btrfs>
 
@@ -82,7 +82,7 @@ my %config_options = (
   # NOTE: the parser always maps "no" to undef
   # NOTE: keys "volume", "subvolume" and "target" are hardcoded
   # NOTE: files "." and "no" map to <undef>
-  timestamp_format            => { default => "long",        accept => [qw( short long long-iso )], context => [qw( global volume subvolume )] },
+  timestamp_format            => { default => "long",        accept => [qw( short long long-iso human )], context => [qw( global volume subvolume )] },
   snapshot_dir                => { default => undef,         accept_file => { relative => 1, absolute => 1 }, context => [qw( global volume subvolume )] },
   snapshot_name               => { c_default => 1,           accept_file => { name_only => 1 }, context => [qw( subvolume )], deny_glob_context => 1 },   # NOTE: defaults to the subvolume name (hardcoded)
   snapshot_create             => { default => "always",      accept => [qw( no always ondemand onchange )], context => [qw( global volume subvolume )] },
@@ -4834,6 +4834,9 @@ sub timestamp($$;$)
   elsif($format eq "debug-iso") {
     $ts = sprintf('%04u-%02u-%02uT%02u:%02u:%02u', $tm[5] + 1900, $tm[4] + 1, $tm[3], $tm[2], $tm[1], $tm[0]);
   }
+  elsif($format eq "human") {
+    return sprintf('%04u-%02u-%02u_%02u-%02u', $tm[5] + 1900, $tm[4] + 1, $tm[3], $tm[2], $tm[1]);
+  }
   else { die; }
 
   if($tm_is_utc) {

doc/btrbk.conf.5.asciidoc

@@ -94,7 +94,7 @@ otherwise.
 
 === Basic Options
 
-*timestamp_format* short|long|long-iso::
+*timestamp_format* short|long|long-iso|human::
     Timestamp format used as postfix for new snapshot subvolume
     names. Defaults to ``long''.
 +
@@ -105,6 +105,7 @@ endif::backend-docbook,backend-manpage[]
 *short*;;    +YYYYMMDD[_N]+  (e.g. "20150825", "20150825_1")
 *long*;;     +YYYYMMDD<T>hhmm[_N]+  (e.g. "20150825T1531")
 *long-iso*;; +YYYYMMDD<T>hhmmss&plusmn;hhmm[_N]+  (e.g. "20150825T153123+0200")
+*human*;;    +YYYY\<\->MM\<\->DD<_>hh\<\->mm[_N]+  (e.g. "2015-08-25_15-31")
 --
 +
 Note that a postfix "_N" is appended to the timestamp if a snapshot or