I know for the reverse procedure, there are lots of methods available. But how can I change my fasta file with sequences like:

    >gi|189094002
    MDDAELNAIRQARLAELQRNAAGGGSSTNPSSSSSGGAQDSAQENMTITILNRVLTNEARERLSRQQTKITFNRKNIAADDDEDDDDFFD
    >gi|68485955
    MDDAELNAIRQARLAELQRNAAGGGSSTNPSSSSSGGAQDSAQENMTITILNRVLTNEARERLSRVKIVRRDSQQKQQTKITFNRKNIAGDDEDDDDFFD

to like:




    >gi|189094002
    MDDAELNAIRQARLAELQRNAAGGGSSTNPSSSSSGGAQDSAQENMTITILNRVLTNEARERLSR
    QQTKITFNRKNIAADDDEDDDDFFD
    >gi|68485955
    MDDAELNAIRQARLAELQRNAAGGGSSTNPSSSSSGGAQDSAQENMTITILNRVLTNEARERLSR
    VKIVRRDSQQKQQTKITFNRKNIAGDDEDDDDFFD

I know its just about inserting line breaks in each sequence, but  is there any way that I can check whether the fasta file is single line fasta or not, and if is, add line breaks in each sequence..

Ps. I am using windows..

Thanks for your consideration







[seqmagick](https://github.com/GuangchuangYu/seqmagick):

```
library(seqmagick)
fa_read(INFILE) %>% fa_write(OUTFILE, type = "interleaved")
```