$ valgrind --leak-check=full perl -e1
==5030== Memcheck, a memory error detector.
==5030== Copyright (C) 2002-2005, and GNU GPL'd, by Julian Seward et al.
==5030== Using LibVEX rev 1471, a library for dynamic binary translation.
==5030== Copyright (C) 2004-2005, and GNU GPL'd, by OpenWorks LLP.
==5030== Using valgrind-3.1.0, a dynamic binary instrumentation framework.
==5030== Copyright (C) 2000-2005, and GNU GPL'd, by Julian Seward et al.
==5030== For more details, rerun with: -v
==5030== 
==5030== 
==5030== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 21 from 1)
==5030== malloc/free: in use at exit: 46,178 bytes in 549 blocks.
==5030== malloc/free: 654 allocs, 105 frees, 53,220 bytes allocated.
==5030== For counts of detected errors, rerun with: -v
==5030== searching for pointers to 549 not-freed blocks.
==5030== checked 325,632 bytes.
==5030== 
==5030== 1,211 (104 direct, 1,107 indirect) bytes in 1 blocks are definitely lost in loss record 1 of 3
==5030==    at 0x401A619: malloc (vg_replace_malloc.c:149)
==5030==    by 0x8098B14: Perl_safesysmalloc (in /usr/local/bin/perl)
==5030==    by 0x809AA63: Perl_my_setenv (in /usr/local/bin/perl)
==5030==    by 0x8060011: perl_parse (in /usr/local/bin/perl)
==5030==    by 0x805E417: main (in /usr/local/bin/perl)
==5030== 
==5030== LEAK SUMMARY:
==5030==    definitely lost: 104 bytes in 1 blocks.
==5030==    indirectly lost: 1,107 bytes in 24 blocks.
==5030==      possibly lost: 0 bytes in 0 blocks.
==5030==    still reachable: 44,967 bytes in 524 blocks.
==5030==         suppressed: 0 bytes in 0 blocks.
==5030== Reachable blocks (those to which a pointer was found) are not shown.
==5030== To see them, rerun with: --show-reachable=yes
$