Number of Syscalls ID dash yash ash mksh bash-5 bash-4 zsh ysh osh Description 01 40 49 64 59 144 156 194 4593 5913 echo hi 02 90 100 114 117 207 232 250 4656 4641 date 03 90 100 114 131 207 232 250 4656 4641 date ; 04 98 116 123 132 269 292 281 4662 4660 trap 'echo mytrap' EXIT; date 05 98 112 123 132 233 256 278 4668 4668 date; echo hi 06 91 104 115 132 209 256 254 4668 4653 echo hi; date 07 132 149 158 189 268 313 318 4706 4691 date; date 08 132 149 158 189 292 313 319 4716 4701 { date; date; } 09 132 149 158 189 292 313 319 4716 4701 date; { date; } 10 149 171 175 198 310 331 373 4728 4728 . _tmp/sourced.sh 11 40 50 64 73 174 184 203 4593 4593 (echo hi) 12 90 101 114 133 239 262 256 4656 4641 (date) 13 90 102 114 133 247 270 262 4666 4651 ( ( date ) ) 14 98 114 123 134 249 272 290 4660 4660 ( ( date ) ); echo hi 15 91 105 115 134 241 264 260 4668 4653 echo hi; (date) 16 91 105 115 134 241 264 260 4668 4653 echo hi; (date;) 17 41 53 65 74 175 185 207 4618 4604 echo hi; (echo hi;) 18 92 108 116 147 242 285 264 4661 4646 echo hi; (echo hi; date) 19 48 62 73 74 176 186 231 4611 4611 ( echo hi ); echo hi 20 96 105 118 139 234 257 256 4667 4650 date > /tmp/redir.txt 21 93 119 117 141 242 265 259 4667 4650 (date;) > /tmp/sentence.txt 22 163 167 187 231 321 355 363 4737 4718 date 2> /tmp/stderr.txt | wc -l 23 48 57 70 66 154 166 201 4604 4604 echo hi > /tmp/redir.txt 24 43 60 67 81 177 187 205 4618 4604 (echo hi;) > /tmp/sentence.txt 25 115 119 139 174 264 285 312 4690 4671 echo hi 2> /tmp/stderr.txt | wc -l 26 98 113 123 146 262 284 287 4668 4668 (date; echo hi) 27 106 124 131 154 250 292 293 4677 4675 echo $(date) 28 55 73 81 93 185 194 237 4628 4626 echo $(echo hi) 29 106 125 131 154 279 300 299 4677 4675 echo $( ( date ) ) 30 114 138 140 169 282 303 328 4686 4684 echo $( ( date ); echo hi ) 31 48 62 73 74 176 186 231 4611 4611 ( echo hi ); echo done 32 157 162 183 226 318 352 360 4738 4719 date | wc -l 33 157 177 183 226 318 352 360 4603 4738 ! date | wc -l 34 107 112 133 167 261 282 310 4690 4670 echo a | wc -l 35 107 112 133 167 261 282 353 4681 4662 command echo a | wc -l 36 157 170 183 227 318 380 360 4730 4711 command date | wc -l 37 157 186 183 226 318 380 360 4595 4730 ! command date | wc -l 38 157 162 183 226 326 360 366 4738 4719 ( date ) | wc -l 39 140 171 195 200 298 318 319 4708 4708 date | read x 40 108 115 134 168 262 283 289 4682 4663 { echo a; echo b; } | wc -l 41 110 132 135 169 264 285 320 4684 4684 { echo a; echo b; } | wc -l; echo done 42 159 167 185 241 350 383 344 4733 4714 { echo a; date; } | wc -l 43 108 115 134 168 262 283 317 4682 4663 ( echo a; echo b ) | wc -l 44 108 116 134 168 272 293 324 4682 4663 ( echo a; echo b ) | ( wc -l ) 45 109 120 135 183 302 322 303 4683 4664 { echo prefix; ( echo a; echo b ); } | ( wc -l ) 46 54 66 78 82 201 210 233 4618 4618 echo hi & wait 47 104 117 128 142 258 280 283 4657 4657 date & wait 48 117 137 139 178 287 307 325 4678 4678 echo hi | wc -l & wait 49 167 188 192 237 344 377 374 4735 4735 date | wc -l & wait 50 105 125 129 143 296 318 290 4663 4661 trap 'echo mytrap' EXIT; date & wait 51 168 196 190 238 398 431 381 4731 4729 trap 'echo mytrap' EXIT; date | wc -l & wait 52 112 133 136 153 326 346 318 4673 4673 { trap 'echo mytrap' EXIT; date; } & wait TOTAL 5486 6240 6803 8061 13481 14764 15229 242884 244004