In order to see the list of predefined color names in emacs do:
Suppose you want to insert a line at 10th line of all files in current directory (e.g. all txt files). The following command creates a backup for each file with the extension “.bak” and changes the files inplace.
sed -i'.bak' '10iThis is the inserted line' *.txt
To convert from ISO-8859-7 to UTF-8:
iconv --from-code=ISO-8859-7 --to-code=UTF-8 iso-file.txt > utf8-file.txt
To list all available encodings supported by iconv:
iconv is part of glibc.