"sasa<app>sasa<server>sasa<client>ddsdds".scan(/\<([^>]*)\>/)

JavaScript的

 var string = "sasa<app>sasa<server>sasa<client>ddsdds";
string.match(/\b\w+(?=\>)/g);

Ruby的

 string = "sasa<app>sasa<server>sasa<client>ddsdds";
array = string.scan(/\b\w+(?=\>)/);

$str = "sasa <app> sasa <server> sasa <client> ddsdds";
preg_match_all("/<(.*)>/U", $str, $matches); </client> </server> </app>

Perl的，抛个砖头，期待更简洁的代码

 my $st="sasa<app>sasa<server>sasa<client>ddsdds";
my @arr;
push @arr, $1 while ($st=~s/<([^>]+)>//);

print join(",", @arr);