How to remove leading whitespace from each line in a file

Question

I have a file that looks something like this:

for (i = 0; i < 100; i++)
    for (i = 0; i < 100; i++)
  for (i = 0; i < 100; i++)
       for (i = 0;         


        

Answer 1

Use:

sed -e **'s/^[ \t]*//'**  name_of_file_from_which_you_want_to_remove_space > 'name _file_where_you_want_to_store_output'

For example:

sed -e 's/^[ \t]*//'  file1.txt > output.txt

Note:

s/: Substitute command ~ replacement for pattern (^[ \t]*) on each addressed line

^[ \t]*: Search pattern ( ^ – start of the line; [ \t]* match one or more blank spaces including tab)

//: Replace (delete) all matched patterns