subroutine help(unit)
integer, intent(in) :: unit
write(unit, '(a, *(1x, a))') &
"Usage: "//prog_name//" [options] <input> <output>"
write(unit, '(a)') &
"", &
"Read structure from input file and writes it to output file.", &
"The format is determined by the file extension or the format hint", &
""
write(unit, '(2x, a, t25, a)') &
"-i, --input <format>", "Hint for the format of the input file", &
"-o, --output <format>", "Hint for the format of the output file", &
"--normalize", "Normalize all element symbols to capitalized format", &
"--template <file>", "File to use as template to fill in meta data", &
"", "(useful to add back SDF or PDB annotions)", &
"--template-format <format>", "", "", "Hint for the format of the template file", &
"--ignore-dot-files", "Do not read charge and spin from .CHRG and .UHF files", &
"--version", "Print program version and exit", &
"--help", "Show this help message"
write(unit, '(a)')
end subroutine help