How to convert GTF format into BED12 or BIGBED format?

#see below for UPDATES that include more shorter ways of conversions

#How to convert GTF format into BED12 format (Human-hg19)?

#How to convert GTF or BED format into BIGBED format?

#Why BIGBED (If GTF or BED file is very large to upload in UCSC, you can use trackHubs. However trackHubs do not accept either of the formats. Therefore you would need bigBed format)

#First, download UCSC scripts

wget http://hgdownload.cse.ucsc.edu/admin/exe/linux.x86_64/gtfToGenePred

wget http://hgdownload.cse.ucsc.edu/admin/exe/linux.x86_64/genePredToBed

wget http://hgdownload.cse.ucsc.edu/admin/exe/linux.x86_64/bedToBigBed

#Second, download chromosome sizes and filter out unnecessary chromosomes

wget http://hgdownload.cse.ucsc.edu/goldenPath/hg19/bigZips/hg19.chrom.sizes

grep -v chrM hg19.chrom.sizes|grep -v _hap|grep -v Un_gl|grep -v random>hg19.chrom.filtered.sizes

rm hg19.chrom.sizes

#Third, make them executable

chmod +x gtfToGenePred genePredToBed bedToBigBed

#Convert Gtf to genePred

./gtfToGenePred 1st_53_tissues.combined.gtf 1st_53_tissues.combined.genePred

#Convert genPred to bed12

./genePredToBed 1st_53_tissues.combined.genePred 1st_53_tissues.combined.bed12

#sort bed12

sort -k1,1 -k2,2n 1st_53_tissues.combined.bed12>1st_53_tissues.combined.sorted.bed

#Convert sorted bed12 to bigBed (useful for trackhubs)

./bedToBigBed 1st_53_tissues.combined.sorted.bed hg19.chrom.filtered.sizes 1st_53_tissues.combined.bb