Print Specific Line Contents in File

perl.sh

perl -n -e 'print if $. == 15' file.txt

# where $_ is line's content

# -n creates: while (<>) { ... } around files, making Perl iterate over lines
# -e option's value goes into { ... }

# https://perldoc.perl.org/perlvar#$.

perl_argv.sh

perl -n -e 'print if ARGV -> input_line_number == 15' file.txt

# the same as above, but using IO::Handle object method to access the line number

# https://perldoc.perl.org/IO::Handle#METHODS

sed.sh

sed -n '15p' file.txt

# Or: sh -c "sed -n '15p' `realpath file.txt`"