The example below uses head with -n 50 to read the first 50 lines of large_file.txt and then copy them into a new file called first_50_rows.txt. An easy method on a Unix/Linux system is the head command. If your file is too large to easily open in a text editor, there are various ways to sample portions of it into a separate, smaller file on the command line. Many text editors also give character counts for cursor placement, which makes it easier to spot a pattern in the character counts. If the data all line up tidily, it’s probably a fixed width file. If you’re trying to read a fixed width file as a csv or tsv and getting mangled results, try opening it in a text editor.

Upon initial examination, a fixed width file can look like a tab separated file when white space is used as the padding character. For example: in a file with three fields, the first field could be 6 characters, the second 20, and the last 9. Note: All fields in a fixed width file do not need to have the same character count. Values can be left or right aligned in a field and alignment must be consistent for all fields in the file.Ī thorough description of a fixed width file is available here.White space is a common padding character. Any character can be used as a padding character as long as it is consistent throughout the file.When values don’t consume the total character count for a field, a padding character is used to bring the character count up to the total for that field.

This is convenient if you’re looking at raw data files in a text editor, but less ideal when you need to programmatically work with the data.įixed width files have a few common quirks to keep in mind: This creates files with all the data tidily lined up with an appearance similar to a spreadsheet when opened in a text editor. A fixed width file is similar to a csv file, but rather than using a delimiter, each field has a set number of characters.

How to open a large text file in excel