printf(1)             UNIX System V(Essential Utilities)              printf(1)


NAME
      printf - print formatted output

SYNOPSIS
      printf format [arg . . .]

DESCRIPTION
      The printf command converts, formats, and prints its args under control
      of the format.  It fully supports conversion specifications for strings
      (%s descriptor); however, the results are undefined for the other
      conversion specifications supported by printf(3S).

      format    a character string that contains three types of objects:  1)
                plain characters, which are simply copied to the output stream;
                2) conversion specifications, each of which results in fetching
                zero or more args; and 3) C-language escape sequences, which
                are translated into the corresponding characters.

      arg       string(s) to be printed under the control of format.  The
                results are undefined if there are insufficient args for the
                format.  If the format is exhausted while args remain, the
                excess args are simply ignored.

      Each conversion specification is introduced by the character %.  After
      the %, the following appear in sequence:

            An optional field, consisting of a decimal digit string followed by
            a $, specifying the next arg to be converted.  If this field is not
            provided, the arg following the last arg converted is used.

            An optional decimal digit string specifying a minimum field width.
            If the converted value has fewer characters than the field width,
            it is padded on the left (or right, if the left-adjustment flag `-'
            has been given) to the field width.  The padding is with blanks
            unless the field width digit string starts with a zero, in which
            case the padding is with zeros.

            An optional precision that gives the maximum number of characters
            to be printed from a string in %s conversion.  The precision takes
            the form of a period (.)  followed by a decimal digit string; a
            null digit string is treated as zero (nothing is printed).  Padding
            specified by the precision overrides the padding specified by the
            field width.  That is, if precision is specified, its value is used
            to control the number of characters printed.

            A field width or precision or both may be indicated by an asterisk
            (*) instead of a digit string.  In this case, an integer arg
            supplies the field width or precision.  The arg that is actually
            converted is not fetched until the conversion letter is seen, so
            the args specifying field width or precision must appear before the
            arg (if any) to be converted.  A negative field width argument is
            taken as a `-' (left-adjustment) flag followed by a positive field


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printf(1)             UNIX System V(Essential Utilities)              printf(1)


            width.  If the precision argument is negative, it is changed to
            zero (nothing is printed).  In no case does a non-existent or small
            field width cause truncation of a field; if the result of a
            conversion is wider than the field width, the field is simply
            expanded to contain the conversion result.

      The conversion characters and their meanings are:

      %s    The arg is taken to be a string and characters from the string are
            printed until a null character (\0) is encountered or the number of
            characters indicated by the precision specification is reached.  If
            the precision is missing, it is taken to be infinite, so all
            characters up to the first null character are printed.  A null
            value for arg yields undefined results.

      %%    Print a %; no argument is converted.

EXAMPLES
      The command

            printf '%s %s %s\n' Good Morning World

      results in the output:

            Good Morning World

      The following command produces the same output.

            printf '%2$s %s %1$s\n' World Good Morning

      Here is an example that prints the first 6 characters of $PATH left-
      adjusted in a 10-character field:

            printf 'First 6 chars of %s are %-10.6s.\n' $PATH $PATH

      If $PATH has the value /usr/bin:/usr/local/bin, then the above command
      would print the following output:

            First 6 chars of /usr/bin:/usr/local/bin are /usr/b    .

SEE ALSO
      printf(3S) in the Programmer's Reference Manual












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