File: sbs.sh 1 #!/bin/sh 2 3 # The MIT License (MIT) 4 # 5 # Copyright © 2020-2025 pacman64 6 # 7 # Permission is hereby granted, free of charge, to any person obtaining a copy 8 # of this software and associated documentation files (the “Software”), to deal 9 # in the Software without restriction, including without limitation the rights 10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 # copies of the Software, and to permit persons to whom the Software is 12 # furnished to do so, subject to the following conditions: 13 # 14 # The above copyright notice and this permission notice shall be included in 15 # all copies or substantial portions of the Software. 16 # 17 # THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 # SOFTWARE. 24 25 26 # sbs [column count...] [filepaths...] 27 # 28 # Side-By-Side lays out lines read from all inputs given into several columns, 29 # separating them with a special symbol. If no named inputs are given, lines 30 # are read from the standard input, instead of files. 31 # 32 # If a column-count isn't given, the script tries to find the most columns 33 # which can fit a reasonable width-limit; when even a single column can't fit 34 # that limit, it simply emits all lines, which is the same as using 1 column. 35 36 37 case "$1" in 38 -h|--h|-help|--help) 39 awk '/^# +sbs /, /^$/ { gsub(/^# ?/, ""); print }' "$0" 40 exit 0 41 ;; 42 esac 43 44 num_columns=0 45 if [ "$(echo "$1" | grep -E '^[+-]?[0-9]+$' 2> /dev/null)" ]; then 46 num_columns="$1" 47 shift 48 fi 49 50 [ "$1" = "--" ] && shift 51 52 # show all non-existing files given 53 failed=0 54 for arg in "$@"; do 55 if [ "${arg}" = "-" ]; then 56 continue 57 fi 58 if [ ! -e "${arg}" ]; then 59 printf "\e[38;2;204;0;0mno file named \"%s\"\e[0m\n" "${arg}" >&2 60 failed=1 61 fi 62 done 63 64 # in case of errors, avoid showing an empty screen 65 if [ "${failed}" -gt 0 ]; then 66 exit 2 67 fi 68 69 command='awk' 70 if [ -e /usr/bin/gawk ]; then 71 command='gawk' 72 fi 73 74 # allow loading lines from multiple files, ensuring no lines are accidentally 75 # joined across inputs 76 awk 1 "$@" | 77 78 # ignore leading UTF-8 BOMs (byte-order marks) and trailing carriage-returns: 79 # the latter in particular will ruin side-by-side output; doing it separately 80 # using `sed` is faster overall for the script 81 sed 's-^\xef\xbb\xbf--; s-\r$--' | 82 83 # before laying out lines side-by-side, expand all tabs, using 4 as the 84 # tabstop width 85 expand -t 4 | 86 87 # lay lines into side-by-side columns 88 ${command} -v num_columns="${num_columns}" ' 89 BEGIN { 90 sep = " █" 91 sep_width = width(sep) 92 total_max_width = 79 93 max_auto_cols = 26 94 95 # num_columns = 0 96 # detect a leading number, and use it as the max-number of columns 97 if (ARGV[1] + 0 != 0) { 98 num_columns = ARGV[1] + 0 99 delete ARGV[1] 100 } 101 } 102 103 # remember all lines; carriage-returns are already removed 104 { lines[NR] = $0 } 105 106 # width counts items in the string given, ignoring ANSI-style sequences 107 function width(s) { 108 gsub(/\x1b\[[0-9;]*[A-Za-z]/, "", s) 109 return length(s) 110 } 111 112 # pick a line using a row-column pair as an index 113 function pick(lines, height, row, col) { 114 return lines[(col - 1) * height + row] 115 } 116 117 # see if a list of lines can fit the number of columns given exactly 118 function fits(lines, line_count, num_cols, height, max_widths, i, j, w, l) { 119 height = ceil(line_count / num_cols) 120 121 # prevent too many empty columns 122 if (height * num_cols - line_count >= height) { 123 return 0 124 } 125 126 for (i = 1; i <= height; i++) { 127 for (j = 1; j <= num_cols; j++) { 128 w = width(pick(lines, height, i, j)) 129 if (w > total_max_width) return 0 130 if (max_widths[j] < w) max_widths[j] = w 131 } 132 } 133 134 for (i = 1; i <= height; i++) { 135 w = 0 136 137 for (j = 1; j <= num_cols; j++) { 138 if (j > 1) w += sep_width 139 140 l = pick(lines, height, i, j) 141 if (j > 1 && l != "") w++ 142 143 w += width(l) 144 145 if (j < num_cols) { 146 pad = max_widths[j] - width(l) 147 if (pad > 0) { 148 if (l == "") pad++ 149 w += pad 150 } 151 } 152 153 if (w > total_max_width) return 0 154 } 155 } 156 157 return 1 158 } 159 160 # auto-detect an appropriate column-count for the list of lines given 161 function find_max_fit(lines, num_columns) { 162 if (!fits(lines, NR, 1)) { 163 return 1 164 } 165 166 for (num_columns = max_auto_cols; num_columns >= 2; num_columns--) { 167 if (fits(lines, NR, num_columns)) { 168 return num_columns 169 } 170 } 171 return 1 172 } 173 174 # round up non-integers 175 function ceil(n) { 176 return (n % 1) ? n - (n % 1) + 1 : n 177 } 178 179 END { 180 # prevent errors when input has no lines 181 if (NR < 1) exit 182 183 # auto-fit when given a non-positive count, or when not given a count 184 if (num_columns < 1) num_columns = find_max_fit(lines) 185 186 # prevent column-count from exceeding the number of input lines 187 if (num_columns > NR) num_columns = NR 188 189 # emit a single column as lines, quitting right away 190 if (num_columns < 2) { 191 for (i = 1; i <= NR; i++) print lines[i] 192 exit 193 } 194 195 # prevent a trailing empty column 196 num_lines = ceil(NR / num_columns) 197 if (num_lines * num_columns - NR >= num_lines) { 198 num_columns-- 199 } 200 201 num_lines = ceil(NR / num_columns) 202 for (i = 1; i <= num_lines; i++) { 203 for (j = 1; j <= num_columns; j++) { 204 w = width(pick(lines, num_lines, i, j)) 205 if (max_widths[j] < w) max_widths[j] = w 206 } 207 } 208 209 widest = 0 210 for (i in max_widths) { 211 if (widest < max_widths[i]) widest = max_widths[i] 212 } 213 214 # emit lines side by side 215 for (i = 1; i <= num_lines; i++) { 216 for (j = 1; j <= num_columns; j++) { 217 l = pick(lines, num_lines, i, j) 218 219 if (j > 1) { 220 printf "%s", sep 221 if (j != num_columns || l != "") printf " " 222 } 223 224 printf "%s", l 225 226 if (j < num_columns) { 227 pad = max_widths[j] - width(l) 228 if (pad > 0) printf "%*s", pad, "" 229 } 230 } 231 232 print "" 233 } 234 } 235 ' | 236 237 # view the result interactively 238 less -MKiCRS