The Program code: Code: use strict; use warnings; my @register_list; open (FILE, "Peint_FcN.xml"); while (my $line = <FILE>) { if ($line =~ m/<Register>/) { my $nextline =<FILE>; if ($nextline =~ /^(.*)<\/Register/) { { push(@register_list, $1); } else { print "You have a problem \n"; } } } close (FILE); foreach (sort(@register_list)) { #$_=~ s/_u/_1/g; print $_ . "\n"; } OUTPUT: CHIP_FRA_u_REF_CLK_SEL[4:0] CHIP_FRAN_u_REF_DIV_K[7:0] CHIP_FRAN_u_REF_DIV_SEL FRANu_FRN_BANDSEL_BYP_EN FRCNu_FRN_BIAS_TRIM FRCNu_FRN_BW_CNTL[4:0] FRCNu_FRN_CMSEL FRCNu_FRN_CORE_SEL FRCNu_FRN_CTUNE_BYP_EN FRCNu_FRN_CXC_BANDSEL[4:0] FRCNu_FRN_CXC_BANDSEL_STA[4:0] FRCNu_FRN_CXC_CFA_AUTO_ACQ_BYP FRCNu_FRN_CXC_CFA_BANDSEL_MAX FRCNu_FRN_CXC_CFA_CNTR_RANK_ADJ FRCNu_FRN_CXC_CFA_FAIL_STA FRCNu_FRN_CXC_CFA_LUT_BANDSEL[30:0] FRCNu_FRN_CXC_CFA_LUT_CD_UNLCK FRCNu_FRN_CXC_CFA_LUT_CK_DELAY FRCNu_FRN_CXC_CFA_LUT_CNTR_RANK FRCNu_FRN_CXC_CFA_LUT_FILTER_LEN[20:0] FRCNu_FRN_CXC_CFA_LUT_LOL_MARGIN FRCNu_FRN_CXC_CFA_LUT_OWRT The code is working exactly the way I have written it work, but I want to work such that CHIP_FRA_u_REF_CLK_SEL CHIP_FRAN_u_REF_DIV_K CHIP_FRAN_u_REF_DIV_SEL FRANu_FRN_BANDSEL_BYP_EN FRCNu_FRN_BIAS_TRIM FRCNu_FRN_BW_CNTL FRCNu_FRN_CMSEL FRCNu_FRN_CORE_SEL FRCNu_FRN_CTUNE_BYP_EN FRCNu_FRN_CXC_BANDSEL FRCNu_FRN_CXC_BANDSEL_STA FRCNu_FRN_CXC_CFA_AUTO_ACQ_BYP FRCNu_FRN_CXC_CFA_BANDSEL_MAX FRCNu_FRN_CXC_CFA_CNTR_RANK_ADJ FRCNu_FRN_CXC_CFA_FAIL_STA FRCNu_FRN_CXC_CFA_LUT_BANDSEL FRCNu_FRN_CXC_CFA_LUT_CD_UNLCK FRCNu_FRN_CXC_CFA_LUT_CK_DELAY FRCNu_FRN_CXC_CFA_LUT_CNTR_RANK FRCNu_FRN_CXC_CFA_LUT_FILTER_LEN FRCNu_FRN_CXC_CFA_LUT_LOL_MARGIN FRCNu_FRN_CXC_CFA_LUT_OWRT It takes away the numbers at the end of the string. I need help how to change the regular expression I used in the code to make it work the way I need it to, so it only prints the string and not the numbers at the end. Sorry It's so long. Thank You in advance.
