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View large file in Unix



You might had this experience many times while working in day to day Unix environments..


Viewing a Unix file very common in any Unix based task, however, there are large files in form of any log or any other data. Viewing such files really annoying to any administrator when this hits the following error.

 Out of memory saving lines for undo - try using ed
:
The reason why above error, default maximum lines can be displayed by "vi" editor is 1,048,560 so anything file more than 1,048,560 lines will not be displayed with "vi" editor.

May be below will show what you're looking for but will not allow much flexibility to view complete file

View the first 200 records

$head -n 200 yourfile.log |pg

to view the last 200 records

$tail -200 yourfile.log


How to solve this problem

"-y" switch of "vi" editor allows to overrides the maximum line setting of 1,048,560 with any value greater than 1024. You should request twice the number of lines that you require because the vi editor uses the extra lines for buffer manipulation.

Example

Below the command will set vi editors to display 99999999 lines at run time.

$vi -y 99999999 yourfile.log

More information you can find out with "man vi".

Hope this helps. Please let me know in case any queries.

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