multiple bam files one command

[cmccabe]

I have multiple .bam files in a directory that I would like to run the following command on:

samtools view -H Input.bam | sed '/^@PG/d' | samtools reheader - Input.bam > Input_newheader.bam

The command works great for one file, but I am trying to use that command on all .bam file in a directory (/home/cmccabe/Desktop/NGS).

to do multiple? or is there a better way? Thank you .

find *bam | parallel 'samtools view -H Input.bam | sed '/^@PG/d' | samtools reheader - Input.bam > Input_newheader.bam'

[dpryan]

for f in *.bam
do
prefix=${f%%.bam}
samtools view -H $f | sed '/^@PG/d' | samtools reheader - $f > ${prefix}_newheader.bam
done

This is going to quickly become IO bound, so you're unlikely to see much benefit from parallel. BTW, to do this with parallel, the simplest method is to just write a shell script that takes a single file as input and use that with parallel.

[cmccabe]

If all the bam files are stored on a separate drive (/media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215), and the output gets re-directed to (/home/cmccabe/Desktop/NGS/pool_I_090215)will the below work?

cd "/home/cmccabe/Desktop/NGS" -- path to samtools

for f in *.bam
do
prefix=${f%%.bam}
samtools view -H /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/$f | sed '/^@PG/d' | samtools reheader - /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/$f > /home/cmccabe/Desktop/NGS/pool_I_090215/${prefix}_newheader.bam
done

Thank you

[dpryan]

"*.bam" is looking in the current working directory, so no, that won't work. If you said "/media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/*.bam" then note that you would need to do something like:

bname=`basename $f`
pref=${bname%%.bam}

That would strip the path to the file appropriately. You would also then just use $f instead of /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/$f. For why that's the case, run:

for f in /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/*.bam
do
echo $f
done

[cmccabe]

Makes sense, so I tried: the bold is the output so why is it looking for those files? Thank you for your help.

cmccabe@HPZ640:~/Desktop/NGS$ for f in /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/*.bam; do prefix=${f%%.bam}; samtools view -H $f | sed '/^@PG/d' | samtools reheader - $f > /home/cmccabe/Desktop/NGS/pool_I_090215${prefix}_newheader.bam; done
[B]bash: /home/cmccabe/Desktop/NGS/pool_I_090215/media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/IonXpress_008_150902_newheader.bam: No such file or directory
bash: /home/cmccabe/Desktop/NGS/pool_I_090215/media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/IonXpress_015_rawlib_newheader.bam: No such file or directory
bash: /home/cmccabe/Desktop/NGS/pool_I_090215/media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/IonXpress_016_150902_newheader.bam: No such file or directory[/B]

[dpryan]

You forgot the basename line.

[cmccabe]

I thought I got it but I am a bit confused:

bname=`basename $f`
pref=${bname%%.bam}
for f in /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/*.bam
do
prefix=${f%%.bam}
samtools view -H $f | sed '/^@PG/d' | samtools reheader - $f > /home/cmccabe/Desktop/NGS/pool_I_090215/${prefix}_newheader.bam
done

gives the below error:

cmccabe@HPZ640:~$ cd "/home/cmccabe/Desktop/NGS"
cmccabe@HPZ640:~/Desktop/NGS$ bname=`basename $f`
basename: missing operand
Try 'basename --help' for more information.
cmccabe@HPZ640:~/Desktop/NGS$ pref=${bname%%.bam}
cmccabe@HPZ640:~/Desktop/NGS$ for f in /media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/*.bam
> do
> prefix=${f%%.bam}
> samtools view -H $f | sed '/^@PG/d' | samtools reheader - $f > /home/cmccabe/Desktop/NGS/pool_I_090215/${prefix}_newheader.bam
> done
bash: /home/cmccabe/Desktop/NGS/pool_I_090215//media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/IonXpress_008_150902_newheader.bam: No such file or directory
bash: /home/cmccabe/Desktop/NGS/pool_I_090215//media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/IonXpress_015_rawlib_newheader.bam: No such file or directory
bash: /home/cmccabe/Desktop/NGS/pool_I_090215//media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/IonXpress_016_150902_newheader.bam: No such file or directory

Thank you .

[dpryan]

When you run basename, $f hasn't yet been defined...

I'm actually not going to explicitly tell you the solution to this, you should be able to figure it out given a bit of playing around and noting the error message.

[cmccabe]

So here is the command:

/media/cmccabe/C2F8EFBFF8EFAFB9/pool_I_090215/*.bam ; do     bname=`basename $f`;     pref=${bname%%.bam};     samtools view -H $f | sed '/^@PG/d' | samtools reheader - $f > /home/cmccabe/Desktop/NGS/pool_I_090215/${pref}_newheader.bam; done

This seems to work great, thank you for your help .