raw937/oneliners

One liners and useful scripts for computational biology

Useful one-liners for computational biology

Convert

Convert fastq to fasta

Option 1

sed -n '1~4s/^@/>/p;2~4p' file.fastq >file.fasta

Option 2

sed '/^@/!d;s//>/;N' file.fastq >file.fasta

Convert multiline fasta to single line

Option 1

perl -pe '/^>/ ? print "\n" : chomp' multi-line.fasta >single-line.fasta

Option 2

awk '/^>/ {printf("\n%s\n",$0);next; } { printf("%s",$0);}  END {printf("\n");}' < multi-line.fasta >single-line.fasta

Option 3

perl -pe 'chomp unless /^>/' multi-line.fasta >single-line.fasta

Option 4

awk '/^>/ { if(NR>1) print "";  printf("%s\n",$0); next; } { printf("%s",$0);}  END {printf("\n");}' < multi-line.fasta >single-line.fasta

Option 5

awk 'BEGIN{RS=">"}NR>1{sub("\n","\t"); gsub("\n",""); print RS$0}' < multi-line.fasta >single-line.fasta

Remove contigs based on header (after transform to single line)

grep -A1 -f list_to_filter contigs.fasta >rm_contigs.fasta
grep -v -f rm_contigs.fasta contigs.fasta >output.fasta

Convert multi-line fasta to a single line fasta (contig files)

awk '/^>/ {printf("\n%s\n",$0);next; } { printf("%s",$0);}  END {printf("\n");}' < file.fa > out.fa

Convert csv to tsv

sed -E 's/("([^"]*)")?,/\2\t/g' file.csv >> file.tsv

Convert Sam to fastq

cat file.sam | grep -v ^@ | awk '{print "@"$1"\n"$10"\n+\n"$11}' > file.fastq

Copy many files from many directories

find . -name "*.gff" -type f -exec cp {} ./. \;

Count

AWK for rapid fastq read count

awk '{s++}END{print s/4}' file.fastq

Rapid fastq read count (.gz)

zcat file.fastq.gz | echo $((`wc -l`/4))

Grep to count a fasta file

Option 1

grep ">" file.fasta -c

Option 2

grep ">" file.fasta | wc -l 

Grep to count a fastq file

Option 1

grep "@" file.fastq -c

Option 2

grep "@" file.fastq | wc -l 

Rename many files

for i in *NAME*; do mv $i ${i/NAME/NEW_NAME}; done;

SED Commands

Remove spaces in a fasta file

sed -r ‘s/\s+//g’

Make uppercase text in a fasta file

sed 's/[a-z]/\U&/g'

Make lowercase text in a fasta file

sed 's/[A-Z]/\L&/g'

Add a tab after the first space

sed 's/^[ ]*\([^ ]*\) /\1\t/' file.txt >New_file.txt

SAMTOOLS

Convert Sam to Unmapped (sam)

samtools view -S -f 4 file.bam >file_unmapped.sam

Convert Sam to Mapped (sam)

samtools view -S -F 4 file.sam >file_mapped.sam

Convert Bam to Unmapped (bam)

samtools view -b -f 4 file.bam >file_unmapped.bam

Convert Bam to Mapped (bam)

samtools view -b -F 4 file.bam >file_mapped.bam

Convert Bam to fastq

samtools fastq file.bam >file.fastq

MAPPING

Bowtie2

Build Bowtie2 db

bowtie2-build database.fa db

Map paired end/single end (.fq, .fastq, .gz)

Global

Paired-end data (Illumina only)

bowtie2 -p number of threads -x db -1 R1.fastq -2 R2.fastq -S global.sam --very-sensitive

Single-end data (Illumina only)

bowtie2 -p number of threads -x db -q R1.fastq -S global.sam --very-sensitive

Local

Paired-end data (Illumina only)

bowtie2 -p number of threads -x db -1 1.fastq -2 2.fastq -S local.sam --very-sensitive-local

Single-end data (Illumina only)

bowtie2 -p number of threads -x db -q R1.fastq -S local.sam --very-sensitive-local` 

Phylogenetics

Tree annotator

tree_annotator.py annotation.csv treefile output

Contact

The point-of-contact for this project is Dr. Richard Allen White III.
If you have any questions or feedback, please feel free to get in touch by email. Dr. Richard Allen White III - raw937@gmail.com.
Or open an issue.