Bash working code to delete first or last line from file

bash line

sed -i '$ d' filename. The -i flag edits file in place.

bash line

Here you go !delete first line (also BSD/MacOS compatible)

sed '1,1d' file1  >> file1.out

delete last row/line

sed '$d' file2  >> file2.out

bash line

You can use the --in-place (-i) switch:

sed -i '$d' filename

Source: man sed

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