xref: /freebsd-10.2-release/usr.sbin/bsdconfig/share/strings.subr

if [ ! "$_STRINGS_SUBR" ]; then _STRINGS_SUBR=1
#
# Copyright (c) 2006-2012 Devin Teske
# All Rights Reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD: head/usr.sbin/bsdconfig/share/strings.subr 240783 2012-09-21 19:03:25Z dteske $

# f_substr "$string" $start [ $length ]
#
# Simple wrapper to awk(1)'s `substr' function.
#
f_substr()
{
	local string="$1" start="${2:-0}" len="${3:-0}"
	echo "$string" | awk "{ print substr(\$0, $start, $len) }"
}

# f_longest_line_length
#
# Simple wrapper to an awk(1) script to print the length of the longest line of
# input (read from stdin). Supports the newline escape-sequence `\n' for
# splitting a single line into multiple lines.
#
f_longest_line_length_awk='
BEGIN { longest = 0 }
{
	if (split($0, lines, /\\n/) > 1)
	{
		for (n in lines)
		{
			len = length(lines[n])
			longest = ( len > longest ? len : longest )
		}
	}
	else
	{
		len = length($0)
		longest = ( len > longest ? len : longest )
	}
}
END { print longest }
'
f_longest_line_length()
{
	awk "$f_longest_line_length_awk"
}

# f_number_of_lines
#
# Simple wrapper to an awk(1) script to print the number of lines read from
# stdin. Supports newline escape-sequence `\n' for splitting a single line into
# multiple lines.
#
f_number_of_lines_awk='
BEGIN { num_lines = 0 }
{
	num_lines += split($0, unused, /\\n/)
}
END { print num_lines }
'
f_number_of_lines()
{
	awk "$f_number_of_lines_awk"
}

# f_isinteger $arg
#
# Returns true if argument is a positive/negative whole integer.
#
f_isinteger()
{
	local arg="$1"

	# Prevent division-by-zero
	[ "$arg" = "0" ] && return $SUCCESS

	# Attempt to perform arithmetic divison (an operation which will exit
	# with error unless arg is a valid positive/negative whole integer).
	#
	( : $((0/$arg)) ) > /dev/null 2>&1
}

fi # ! $_STRINGS_SUBR