xref: /freebsd/usr.sbin/bsdconfig/share/strings.subr (revision bc3f5ec90bde2f3a5e4021d133c89793d68b8c73)
1if [ ! "$_STRINGS_SUBR" ]; then _STRINGS_SUBR=1
2#
3# Copyright (c) 2006-2013 Devin Teske
4# All rights reserved.
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25# SUCH DAMAGE.
26#
27# $FreeBSD$
28#
29############################################################ INCLUDES
30
31BSDCFG_SHARE="/usr/share/bsdconfig"
32. $BSDCFG_SHARE/common.subr || exit 1
33
34############################################################ GLOBALS
35
36#
37# A Literal newline (for use with f_replace_all(), or IFS, or whatever)
38#
39NL="
40" # END-QUOTE
41
42#
43# Valid characters that can appear in an sh(1) variable name
44#
45# Please note that the character ranges A-Z and a-z should be avoided because
46# these can include accent characters (which are not valid in a variable name).
47# For example, A-Z matches any character that sorts after A but before Z,
48# including A and Z. Although ASCII order would make more sense, that is not
49# how it works.
50#
51VALID_VARNAME_CHARS="0-9ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_"
52
53############################################################ FUNCTIONS
54
55# f_substr "$string" $start [$length]
56#
57# Simple wrapper to awk(1)'s `substr' function.
58#
59f_substr()
60{
61	local string="$1" start="${2:-0}" len="${3:-0}"
62	echo "$string" | awk "{ print substr(\$0, $start, $len) }"
63}
64
65# f_snprintf $var_to_set $size $format [$arguments ...]
66#
67# Similar to snprintf(3), write at most $size number of bytes into $var_to_set
68# using printf(1) syntax (`$format [$arguments ...]'). The value of $var_to_set
69# is NULL unless at-least one byte is stored from the output.
70#
71f_snprintf()
72{
73	local __var_to_set="$1" __size="$2"
74	shift 2 # var_to_set size
75	eval "$__var_to_set"=\$\( printf -- \"\$@\" \| \
76		awk -v max=\"\$__size\" \''
77	{
78		len = length($0)
79		max -= len
80		print substr($0,0,(max > 0 ? len : max + len))
81		if ( max < 0 ) exit
82		max--
83	}'\' \)
84}
85
86# f_sprintf $var_to_set $format [$arguments ...]
87#
88# Similar to sprintf(3), write a string into $var_to_set using printf(1) syntax
89# (`$format [$arguments ...]').
90#
91f_sprintf()
92{
93	local __var_to_set="$1"
94	shift 1 # var_to_set
95	eval "$__var_to_set"=\$\( printf -- \"\$@\" \)
96}
97
98# f_vsnprintf $var_to_set $size $format $format_args
99#
100# Similar to vsnprintf(3), write at most $size number of bytes into $var_to_set
101# using printf(1) syntax (`$format $format_args'). The value of $var_to_set is
102# NULL unless at-least one byte is stored from the output.
103#
104# Example 1:
105#
106# 	limit=7 format="%s"
107# 	format_args="'abc   123'" # 3-spaces between abc and 123
108# 	f_vsnprintf foo $limit "$format" "$format_args" # foo=[abc   1]
109#
110# Example 2:
111#
112# 	limit=12 format="%s %s"
113# 	format_args="   'doghouse'      'foxhound'   "
114# 		# even more spaces added to illustrate escape-method
115# 	f_vsnprintf foo $limit "$format" "$format_args" # foo=[doghouse fox]
116#
117# Example 3:
118#
119# 	limit=13 format="%s %s"
120# 	f_shell_escape arg1 'aaa"aaa' # arg1=[aaa"aaa] (no change)
121# 	f_shell_escape arg2 "aaa'aaa" # arg2=[aaa'\''aaa] (escaped s-quote)
122# 	format_args="'$arg1' '$arg2'" # use single-quotes to surround args
123# 	f_vsnprintf foo $limit "$format" "$format_args" # foo=[aaa"aaa aaa'a]
124#
125# In all of the above examples, the call to f_vsnprintf() does not change. Only
126# the contents of $limit, $format, and $format_args changes in each example.
127#
128f_vsnprintf()
129{
130	eval f_snprintf \"\$1\" \"\$2\" \"\$3\" $4
131}
132
133# f_vsprintf $var_to_set $format $format_args
134#
135# Similar to vsprintf(3), write a string into $var_to_set using printf(1)
136# syntax (`$format $format_args').
137#
138f_vsprintf()
139{
140	eval f_sprintf \"\$1\" \"\$2\" $3
141}
142
143# f_longest_line_length
144#
145# Simple wrapper to an awk(1) script to print the length of the longest line of
146# input (read from stdin). Supports the newline escape-sequence `\n' for
147# splitting a single line into multiple lines.
148#
149f_longest_line_length_awk='
150BEGIN { longest = 0 }
151{
152	if (split($0, lines, /\\n/) > 1)
153	{
154		for (n in lines)
155		{
156			len = length(lines[n])
157			longest = ( len > longest ? len : longest )
158		}
159	}
160	else
161	{
162		len = length($0)
163		longest = ( len > longest ? len : longest )
164	}
165}
166END { print longest }
167'
168f_longest_line_length()
169{
170	awk "$f_longest_line_length_awk"
171}
172
173# f_number_of_lines
174#
175# Simple wrapper to an awk(1) script to print the number of lines read from
176# stdin. Supports newline escape-sequence `\n' for splitting a single line into
177# multiple lines.
178#
179f_number_of_lines_awk='
180BEGIN { num_lines = 0 }
181{
182	num_lines += split(" "$0, unused, /\\n/)
183}
184END { print num_lines }
185'
186f_number_of_lines()
187{
188	awk "$f_number_of_lines_awk"
189}
190
191# f_isinteger $arg
192#
193# Returns true if argument is a positive/negative whole integer.
194#
195f_isinteger()
196{
197	local arg="${1#-}"
198	[ "${arg:-x}" = "${arg#[!0-9]*}" ]
199}
200
201# f_uriencode [$text]
202#
203# Encode $text for the purpose of embedding safely into a URL. Non-alphanumeric
204# characters are converted to `%XX' sequence where XX represents the hexa-
205# decimal ordinal of the non-alphanumeric character. If $text is missing, data
206# is instead read from standard input.
207#
208f_uriencode_awk='
209BEGIN {
210	output = ""
211	for (n = 0; n < 256; n++) pack[sprintf("%c", n)] = sprintf("%%%02x", n)
212}
213{
214	sline = ""
215	slen = length($0)
216	for (n = 1; n <= slen; n++) {
217		char = substr($0, n, 1)
218		if ( char !~ /^[[:alnum:]_]$/ ) char = pack[char]
219		sline = sline char
220	}
221	output = output ( output ? "%0a" : "" ) sline
222}
223END { print output }
224'
225f_uriencode()
226{
227	if [ $# -gt 0 ]; then
228		echo "$1" | awk "$f_uriencode_awk"
229	else
230		awk "$f_uriencode_awk"
231	fi
232}
233
234# f_uridecode [$text]
235#
236# Decode $text from a URI. Encoded characters are converted from their `%XX'
237# sequence into original unencoded ASCII sequences. If $text is missing, data
238# is instead read from standard input.
239#
240f_uridecode_awk='
241BEGIN { for (n = 0; n < 256; n++) chr[n] = sprintf("%c", n) }
242{
243	sline = ""
244	slen = length($0)
245	for (n = 1; n <= slen; n++)
246	{
247		seq = substr($0, n, 3)
248		if ( seq ~ /^%[[:xdigit:]][[:xdigit:]]$/ ) {
249			hex = substr(seq, 2, 2)
250			sline = sline chr[sprintf("%u", "0x"hex)]
251			n += 2
252		} else
253			sline = sline substr(seq, 1, 1)
254	}
255	print sline
256}
257'
258f_uridecode()
259{
260	if [ $# -gt 0 ]; then
261		echo "$1" | awk "$f_uridecode_awk"
262	else
263		awk "$f_uridecode_awk"
264	fi
265}
266
267# f_replaceall $string $find $replace [$var_to_set]
268#
269# Replace all occurrences of $find in $string with $replace. If $var_to_set is
270# either missing or NULL, the variable name is produced on standard out for
271# capturing in a sub-shell (which is less recommended due to performance
272# degradation).
273#
274# To replace newlines or a sequence containing the newline character, use $NL
275# as `\n' is not supported.
276#
277f_replaceall()
278{
279	local __left="" __right="$1"
280	local __find="$2" __replace="$3" __var_to_set="$4"
281	while :; do
282		case "$__right" in *$__find*)
283			__left="$__left${__right%%$__find*}$__replace"
284			__right="${__right#*$__find}"
285			continue
286		esac
287		break
288	done
289	__left="$__left${__right#*$__find}"
290	if [ "$__var_to_set" ]; then
291		setvar "$__var_to_set" "$__left"
292	else
293		echo "$__left"
294	fi
295}
296
297# f_str2varname $string [$var_to_set]
298#
299# Convert a string into a suitable value to be used as a variable name
300# by converting unsuitable characters into the underscrore [_]. If $var_to_set
301# is either missing or NULL, the variable name is produced on standard out for
302# capturing in a sub-shell (which is less recommended due to performance
303# degradation).
304#
305f_str2varname()
306{
307	local __string="$1" __var_to_set="$2"
308	f_replaceall "$__string" "[!$VALID_VARNAME_CHARS]" "_" "$__var_to_set"
309}
310
311# f_shell_escape $string [$var_to_set]
312#
313# Escape $string for shell eval statement(s) by replacing all single-quotes
314# with a special sequence that creates a compound string when interpolated
315# by eval with surrounding single-quotes.
316#
317# For example:
318#
319# 	foo="abc'123"
320# 	f_shell_escape "$foo" bar # bar=[abc'\''123]
321# 	eval echo \'$bar\' # produces abc'123
322#
323# This is helpful when processing an argument list that has to retain its
324# escaped structure for later evaluations.
325#
326# WARNING: Surrounding single-quotes are not added; this is the responsibility
327# of the code passing the escaped values to eval (which also aids readability).
328#
329f_shell_escape()
330{
331	local __string="$1" __var_to_set="$2"
332	f_replaceall "$__string" "'" "'\\''" "$__var_to_set"
333}
334
335# f_shell_unescape $string [$var_to_set]
336#
337# The antithesis of f_shell_escape(), this function takes an escaped $string
338# and expands it.
339#
340# For example:
341#
342# 	foo="abc'123"
343# 	f_shell_escape "$foo" bar # bar=[abc'\''123]
344# 	f_shell_unescape "$bar" # produces abc'123
345#
346f_shell_unescape()
347{
348	local __string="$1" __var_to_set="$2"
349	f_replaceall "$__string" "'\\''" "'" "$__var_to_set"
350}
351
352# f_expand_number $string [$var_to_set]
353#
354# Unformat $string into a number, optionally to be stored in $var_to_set. This
355# function follows the SI power of two convention.
356#
357# The prefixes are:
358#
359# 	Prefix	Description	Multiplier
360# 	k	kilo		1024
361# 	M	mega		1048576
362# 	G	giga		1073741824
363# 	T	tera		1099511627776
364# 	P	peta		1125899906842624
365# 	E	exa		1152921504606846976
366#
367# NOTE: Prefixes are case-insensitive.
368#
369# Upon successful completion, success status is returned; otherwise the number
370# -1 is produced ($var_to_set set to -1 or if $var_to_set is NULL or missing)
371# on standard output. In the case of failure, the error status will be one of:
372#
373# 	Status	Reason
374# 	1	Given $string contains no digits
375# 	2	An unrecognized prefix was given
376# 	3	Result too large to calculate
377#
378f_expand_number()
379{
380	local __string="$1" __var_to_set="$2"
381	local __cp __num __bshift __maxinput
382
383	# Remove any leading non-digits
384	__string="${__string#${__string%%[0-9]*}}"
385
386	# Store the numbers (no trailing suffix)
387	__num="${__string%%[!0-9]*}"
388
389	# Produce `-1' if string didn't contain any digits
390	if [ ! "$__num" ]; then
391		if [ "$__var_to_set" ]; then
392			setvar "$__var_to_set" -1
393		else
394			echo -1
395		fi
396		return 1 # 1 = "Given $string contains no digits"
397	fi
398
399	# Remove all the leading numbers from the string to get at the prefix
400	__string="${__string#"$__num"}"
401
402	#
403	# Test for invalid prefix (and determine bitshift length)
404	#
405	case "$__string" in
406	""|[[:space:]]*) # Shortcut
407		if [ "$__var_to_set" ]; then
408			setvar "$__var_to_set" $__num
409		else
410			echo $__num
411		fi
412		return $SUCCESS ;;
413	[Kk]*) __bshift=10 ;;
414	[Mm]*) __bshift=20 ;;
415	[Gg]*) __bshift=30 ;;
416	[Tt]*) __bshift=40 ;;
417	[Pp]*) __bshift=50 ;;
418	[Ee]*) __bshift=60 ;;
419	*)
420		# Unknown prefix
421		if [ "$__var_to_set" ]; then
422			setvar "$__var_to_set" -1
423		else
424			echo -1
425		fi
426		return 2 # 2 = "An unrecognized prefix was given"
427	esac
428
429	# Determine if the wheels fall off
430	__maxinput=$(( 0x7fffffffffffffff >> $__bshift ))
431	if [ $__num -gt $__maxinput ]; then
432		# Input (before expanding) would exceed 64-bit signed int
433		if [ "$__var_to_set" ]; then
434			setvar "$__var_to_set" -1
435		else
436			echo -1
437		fi
438		return 3 # 3 = "Result too large to calculate"
439	fi
440
441	# Shift the number out and produce it
442	__num=$(( $__num << $__bshift ))
443	if [ "$__var_to_set" ]; then
444		setvar "$__var_to_set" $__num
445	else
446		echo $__num
447	fi
448}
449
450############################################################ MAIN
451
452f_dprintf "%s: Successfully loaded." strings.subr
453
454fi # ! $_STRINGS_SUBR
455