strings.subr revision 256392
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: stable/10/usr.sbin/bsdconfig/share/strings.subr 256392 2013-10-12 19:54:12Z dteske $ 28# 29############################################################ INCLUDES 30 31BSDCFG_SHARE="/usr/share/bsdconfig" 32. $BSDCFG_SHARE/common.subr || exit 1 33 34############################################################ GLOBALS 35 36# 37# Valid characters that can appear in an sh(1) variable name 38# 39# Please note that the character ranges A-Z and a-z should be avoided because 40# these can include accent characters (which are not valid in a variable name). 41# For example, A-Z matches any character that sorts after A but before Z, 42# including A and Z. Although ASCII order would make more sense, that is not 43# how it works. 44# 45VALID_VARNAME_CHARS="0-9ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_" 46 47############################################################ FUNCTIONS 48 49# f_substr "$string" $start [ $length ] 50# 51# Simple wrapper to awk(1)'s `substr' function. 52# 53f_substr() 54{ 55 local string="$1" start="${2:-0}" len="${3:-0}" 56 echo "$string" | awk "{ print substr(\$0, $start, $len) }" 57} 58 59# f_snprintf $var_to_set $size $format ... 60# 61# Similar to snprintf(3), write at most $size number of bytes into $var_to_set 62# using printf(1) syntax (`$format ...'). The value of $var_to_set is NULL 63# unless at-least one byte is stored from the output. 64# 65f_snprintf() 66{ 67 local __var_to_set="$1" __size="$2" 68 shift 2 # var_to_set/size 69 eval "$__var_to_set"=\$\( printf \"\$@\" \| awk -v max=\"\$__size\" \'' 70 { 71 len = length($0) 72 max -= len 73 print substr($0,0,(max > 0 ? len : max + len)) 74 if ( max < 0 ) exit 75 max-- 76 }'\' \) 77} 78 79# f_vsnprintf $var_to_set $size $format $format_args 80# 81# Similar to vsnprintf(3), write at most $size number of bytes into $var_to_set 82# using printf(1) syntax (`$format $format_args'). The value of $var_to_set is 83# NULL unless at-least one byte is stored from the output. 84# 85# Example 1: 86# 87# limit=7 format="%s" 88# format_args="'abc 123'" # 3-spaces between abc and 123 89# f_vsnprintf foo $limit "$format" "$format_args" # foo=[abc 1] 90# 91# Example 2: 92# 93# limit=12 format="%s %s" 94# format_args=" 'doghouse' 'foxhound' " 95# # even more spaces added to illustrate escape-method 96# f_vsnprintf foo $limit "$format" "$format_args" # foo=[doghouse fox] 97# 98# Example 3: 99# 100# limit=13 format="%s %s" 101# f_shell_escape arg1 'aaa"aaa' # arg1=[aaa"aaa] (no change) 102# f_shell_escape arg2 "aaa'aaa" # arg2=[aaa'\''aaa] (escaped s-quote) 103# format_args="'$arg1' '$arg2'" # use single-quotes to surround args 104# f_vsnprintf foo $limit "$format" "$format_args" # foo=[aaa"aaa aaa'a] 105# 106# In all of the above examples, the call to f_vsnprintf() does not change. Only 107# the contents of $limit, $format, and $format_args changes in each example. 108# 109f_vsnprintf() 110{ 111 eval f_snprintf \"\$1\" \"\$2\" \"\$3\" $4 112} 113 114# f_longest_line_length 115# 116# Simple wrapper to an awk(1) script to print the length of the longest line of 117# input (read from stdin). Supports the newline escape-sequence `\n' for 118# splitting a single line into multiple lines. 119# 120f_longest_line_length_awk=' 121BEGIN { longest = 0 } 122{ 123 if (split($0, lines, /\\n/) > 1) 124 { 125 for (n in lines) 126 { 127 len = length(lines[n]) 128 longest = ( len > longest ? len : longest ) 129 } 130 } 131 else 132 { 133 len = length($0) 134 longest = ( len > longest ? len : longest ) 135 } 136} 137END { print longest } 138' 139f_longest_line_length() 140{ 141 awk "$f_longest_line_length_awk" 142} 143 144# f_number_of_lines 145# 146# Simple wrapper to an awk(1) script to print the number of lines read from 147# stdin. Supports newline escape-sequence `\n' for splitting a single line into 148# multiple lines. 149# 150f_number_of_lines_awk=' 151BEGIN { num_lines = 0 } 152{ 153 num_lines += split(" "$0, unused, /\\n/) 154} 155END { print num_lines } 156' 157f_number_of_lines() 158{ 159 awk "$f_number_of_lines_awk" 160} 161 162# f_isinteger $arg 163# 164# Returns true if argument is a positive/negative whole integer. 165# 166f_isinteger() 167{ 168 local arg="$1" 169 170 # Prevent division-by-zero 171 [ "$arg" = "0" ] && return $SUCCESS 172 173 # Attempt to perform arithmetic divison (an operation which will exit 174 # with error unless arg is a valid positive/negative whole integer). 175 # 176 ( : $((0/$arg)) ) > /dev/null 2>&1 177} 178 179# f_uriencode [$text] 180# 181# Encode $text for the purpose of embedding safely into a URL. Non-alphanumeric 182# characters are converted to `%XX' sequence where XX represents the hexa- 183# decimal ordinal of the non-alphanumeric character. If $text is missing, data 184# is instead read from standard input. 185# 186f_uriencode_awk=' 187BEGIN { 188 output = "" 189 for (n = 0; n < 256; n++) pack[sprintf("%c", n)] = sprintf("%%%02x", n) 190} 191{ 192 sline = "" 193 slen = length($0) 194 for (n = 1; n <= slen; n++) { 195 char = substr($0, n, 1) 196 if ( char !~ /^[[:alnum:]_]$/ ) char = pack[char] 197 sline = sline char 198 } 199 output = output ( output ? "%0a" : "" ) sline 200} 201END { print output } 202' 203f_uriencode() 204{ 205 if [ $# -gt 0 ]; then 206 echo "$1" | awk "$f_uriencode_awk" 207 else 208 awk "$f_uriencode_awk" 209 fi 210} 211 212# f_uridecode [$text] 213# 214# Decode $text from a URI. Encoded characters are converted from their `%XX' 215# sequence into original unencoded ASCII sequences. If $text is missing, data 216# is instead read from standard input. 217# 218f_uridecode_awk=' 219BEGIN { for (n = 0; n < 256; n++) chr[n] = sprintf("%c", n) } 220{ 221 sline = "" 222 slen = length($0) 223 for (n = 1; n <= slen; n++) 224 { 225 seq = substr($0, n, 3) 226 if ( seq ~ /^%[[:xdigit:]][[:xdigit:]]$/ ) { 227 hex = substr(seq, 2, 2) 228 sline = sline chr[sprintf("%u", "0x"hex)] 229 n += 2 230 } else 231 sline = sline substr(seq, 1, 1) 232 } 233 print sline 234} 235' 236f_uridecode() 237{ 238 if [ $# -gt 0 ]; then 239 echo "$1" | awk "$f_uridecode_awk" 240 else 241 awk "$f_uridecode_awk" 242 fi 243} 244 245# f_replaceall $string $find $replace [$var_to_set] 246# 247# Replace all occurrences of $find in $string with $replace. If $var_to_set is 248# either missing or NULL, the variable name is produced on standard out for 249# capturing in a sub-shell (which is less recommended due to performance 250# degradation). 251# 252f_replaceall() 253{ 254 local __left="" __right="$1" 255 local __find="$2" __replace="$3" __var_to_set="$4" 256 while :; do 257 case "$__right" in *$__find*) 258 __left="$__left${__right%%$__find*}$__replace" 259 __right="${__right#*$__find}" 260 continue 261 esac 262 break 263 done 264 __left="$__left${__right#*$__find}" 265 if [ "$__var_to_set" ]; then 266 setvar "$__var_to_set" "$__left" 267 else 268 echo "$__left" 269 fi 270} 271 272# f_str2varname $string [$var_to_set] 273# 274# Convert a string into a suitable value to be used as a variable name 275# by converting unsuitable characters into the underscrore [_]. If $var_to_set 276# is either missing or NULL, the variable name is produced on standard out for 277# capturing in a sub-shell (which is less recommended due to performance 278# degradation). 279# 280f_str2varname() 281{ 282 local __string="$1" __var_to_set="$2" 283 f_replaceall "$__string" "[!$VALID_VARNAME_CHARS]" "_" "$__var_to_set" 284} 285 286# f_shell_escape $string [$var_to_set] 287# 288# Escape $string for shell eval statement(s) by replacing all single-quotes 289# with a special sequence that creates a compound string when interpolated 290# by eval with surrounding single-quotes. 291# 292# For example: 293# 294# foo="abc'123" 295# f_shell_escape "$foo" bar # bar=[abc'\''123] 296# eval echo \'$bar\' # produces abc'123 297# 298# This is helpful when processing an argument list that has to retain its 299# escaped structure for later evaluations. 300# 301# WARNING: Surrounding single-quotes are not added; this is the responsibility 302# of the code passing the escaped values to eval (which also aids readability). 303# 304f_shell_escape() 305{ 306 local __string="$1" __var_to_set="$2" 307 f_replaceall "$__string" "'" "'\\''" "$__var_to_set" 308} 309 310# f_shell_unescape $string [$var_to_set] 311# 312# The antithesis of f_shell_escape(), this function takes an escaped $string 313# and expands it. 314# 315# For example: 316# 317# foo="abc'123" 318# f_shell_escape "$foo" bar # bar=[abc'\''123] 319# f_shell_unescape "$bar" # produces abc'123 320# 321f_shell_unescape() 322{ 323 local __string="$1" __var_to_set="$2" 324 f_replaceall "$__string" "'\\''" "'" "$__var_to_set" 325} 326 327# f_expand_number $string [$var_to_set] 328# 329# Unformat $string into a number, optionally to be stored in $var_to_set. This 330# function follows the SI power of two convention. 331# 332# The prefixes are: 333# 334# Prefix Description Multiplier 335# k kilo 1024 336# M mega 1048576 337# G giga 1073741824 338# T tera 1099511627776 339# P peta 1125899906842624 340# E exa 1152921504606846976 341# 342# NOTE: Prefixes are case-insensitive. 343# 344# Upon successful completion, success status is returned; otherwise the number 345# -1 is produced ($var_to_set set to -1 or if $var_to_set is NULL or missing) 346# on standard output. In the case of failure, the error status will be one of: 347# 348# Status Reason 349# 1 Given $string contains no digits 350# 2 An unrecognized prefix was given 351# 3 Result too large to calculate 352# 353f_expand_number() 354{ 355 local __string="$1" __var_to_set="$2" 356 local __cp __num __bshift __maxinput 357 358 # Remove any leading non-digits 359 while :; do 360 __cp="$__string" 361 __string="${__cp#[!0-9]}" 362 [ "$__string" = "$__cp" ] && break 363 done 364 365 # Produce `-1' if string didn't contain any digits 366 if [ ! "$__string" ]; then 367 if [ "$__var_to_set" ]; then 368 setvar "$__var_to_set" -1 369 else 370 echo -1 371 fi 372 return 1 # 1 = "Given $string contains no digits" 373 fi 374 375 # Store the numbers 376 __num="${__string%%[!0-9]*}" 377 378 # Shortcut 379 if [ $__num -eq 0 ]; then 380 if [ "$__var_to_set" ]; then 381 setvar "$__var_to_set" 0 382 else 383 echo 0 384 fi 385 return $SUCCESS 386 fi 387 388 # Remove all the leading numbers from the string to get at the prefix 389 while :; do 390 __cp="$__string" 391 __string="${__cp#[0-9]}" 392 [ "$__string" = "$__cp" ] && break 393 done 394 395 # 396 # Test for invalid prefix (and determine bitshift length) 397 # 398 case "$__string" in 399 ""|[[:space:]]*) # Shortcut 400 if [ "$__var_to_set" ]; then 401 setvar "$__var_to_set" $__num 402 else 403 echo $__num 404 fi 405 return $SUCCESS ;; 406 [Kk]*) __bshift=10 ;; 407 [Mm]*) __bshift=20 ;; 408 [Gg]*) __bshift=30 ;; 409 [Tt]*) __bshift=40 ;; 410 [Pp]*) __bshift=50 ;; 411 [Ee]*) __bshift=60 ;; 412 *) 413 # Unknown prefix 414 if [ "$__var_to_set" ]; then 415 setvar "$__var_to_set" -1 416 else 417 echo -1 418 fi 419 return 2 # 2 = "An unrecognized prefix was given" 420 esac 421 422 # Determine if the wheels fall off 423 __maxinput=$(( 0x7fffffffffffffff >> $__bshift )) 424 if [ $__num -gt $__maxinput ]; then 425 # Input (before expanding) would exceed 64-bit signed int 426 if [ "$__var_to_set" ]; then 427 setvar "$__var_to_set" -1 428 else 429 echo -1 430 fi 431 return 3 # 3 = "Result too large to calculate" 432 fi 433 434 # Shift the number out and produce it 435 __num=$(( $__num << $__bshift )) 436 if [ "$__var_to_set" ]; then 437 setvar "$__var_to_set" $__num 438 else 439 echo $__num 440 fi 441} 442 443############################################################ MAIN 444 445f_dprintf "%s: Successfully loaded." strings.subr 446 447fi # ! $_STRINGS_SUBR 448