DataScience Workbook / 07. Data Acquisition and Wrangling / 1. Remote Data Access / 1.3 Remote Data Preview without Downloading / 1.3.1 Viewing Text Files using UNIX commands


Introduction

Many times the results generated by the bioinformatics programs are either simple text files (tab/comma seperated), pdf files or in some rare cases png/jpeg files. Here we will show you how to view these files without having to download them locally to your machine.

Text files

The text files are the easiest. You can use any of the standard UNIX commands to view them. There are many commands for this purpose such as:

Command Purpose Example Use cases
less view file pagewise with more options less filename use -S to avoid line wrapping, you can use arrow keys to scroll
more view file pagewise more filename use less instead
cat catalogs the contents of a file cat filename you can send the contenst of a file to clipboard or to another file using this command
tac reverse of cat, reverses the order of lines tac filename pipe this to less commad to scroll through the file in reverse
head view first few lines of a file head filename use -n option to change the number of lines displayed. -n 20 displays 20 lines
tail view last few lines of a file tail filename use -n option to change the number of lines displayed. -n 20 displays 20 lines
od octal dump of a file od filename use-c options and pipe it through less. You can see non printable characters with this option (like tab, whitespace, newline etc)

Further Reading


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