Schwartzian transform doesn't seem good for golfing. I tried not to use regexes:

#!/usr/bin/perl -l
@ARGV=qw(mig main_generator migrations django_migrations django_admin_
+log myfoo\bar.txt );

@c=split//,shift;print for map$_->[0],grep$_->[2]>0,sort{$a->[2]<=>$b-
+>[2]or$a->[1]<=>$b->[1]}
map{my$p;$s=$_;my@d;$p>=0 and push@d,$p=index$s,$_,$p for@c;[$s,$d[0],
+$d[-1]-$d[0]]}@ARGV
[download]

Update: Fixed to handle xmxgx: index accepts negative positions and treats them as 0.