Hodie loqui volumus de aliquibus ultimis updates systematis Sherlock [hoc est botrus summus in Stanford University - approx. quae signanter accelerent fasciculi enumerationem in directoriis cum magno numero viscusrum.
Dissimiles regularibus articulis, hoc plus est nuntii in insider quam regulariter in Sherlock laboramus ut eam in usoribus nostris optime curramus. Speramus plura edicere capitula huiusmodi in futuro.
Multis files accipit tempus
Totum auxilium technicum cum quaestione ex usuario incepit. quaestionem dixit de executione ls paucis minutis in directorium cum supra 15 viscus in $SCRATCH [Directorium imaginum temporalium - approx. lane].
Milia files in uno directorio plerumque onus ponunt in ratio lima et certus non commendatur. Usor hoc scivit et confessus est non bonum esse, sed nominavit enumerationem 1000 vicibus velocius fuisse in laptop suo quam Sherlock. Nempe hoc nocuerunt nobis. Sic altius perspeximus.
Quia ls spectat delicatus
Inspeximus quid actu facit ls cum directorium enumeratis, et cur tamdiu processus accipit. De maxime modern distributionibus ls per default ut decurrit ls --color=autocolores enim quisque amat.
Sed colores pulchros pretio veniunt: nam omnis fasciculus ls informationem habere debet de tabella speciei, eius permissionibus, vexillis, attributis extensis et similibus ad colorem proprium eligendum.
Simplex solutio quaestionis est omnino disable color in ls, sed finge flagitium utentium. Nullatenus color output auferas, monstra non sumus.
Sic altius perspeximus. ls colorum entries per environment variabilis LS_COLORSquod positum dircolors(1) configuratione file fundatur dir_colors(5)... Ita, (Et si nescis de files (Fac), tum dir_colors : quamquam omnia).
Sit scriptor propius inspicere
Uter color machinemur utram efficit tarditatem, ambitum experimentalem creavimus;
$ mkdir $SCRATCH/dont
$ touch $SCRATCH/dont/{1..10000} # don't try this at home!
$ time ls --color=always $SCRATCH/dont | wc -l
10000
real 0m12.758s
user 0m0.104s
sys 0m0.699s12,7 secundis pro 10 fasciculis, non valde bonis.
Viam vexillum opus est
--color=always: quamvis se vertit adls --color=autoautemlsdetegit cum non cohaeret cum termino (exempli gratia per fistulam vel cum output redirectionem) et disables fuco si positi suntauto. Callidus guy.
Quid igitur tam diu sumit? Vidimus cum strace:
$ strace -c ls --color=always $SCRATCH/dont | wc -l
10000
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
44.21 0.186617 19 10000 lstat
42.60 0.179807 18 10000 10000 getxattr
12.19 0.051438 5 10000 capget
0.71 0.003002 38 80 getdents
0.07 0.000305 10 30 mmap
0.05 0.000217 12 18 mprotect
0.03 0.000135 14 10 read
0.03 0.000123 11 11 open
0.02 0.000082 6 14 close
[...]
Wow: 10 vocat lstat(), 10 vocat getxattr() (quod omnes deficiunt quod nostrum ambitus attributa ls non habet quaerunt), 10 vocat capget().
Hoc certe ipsum fieri potest.
Facultates attribuunt? non
hoc consilium Nos conatus disable attributum tenendo :
$ eval $(dircolors -b | sed s/ca=[^:]*:/ca=:/)
$ time strace -c ls --color=always $SCRATCH/dont | wc -l
10000
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
98.95 0.423443 42 10000 lstat
0.78 0.003353 42 80 getdents
0.04 0.000188 10 18 mprotect
0.04 0.000181 6 30 mmap
0.02 0.000085 9 10 read
0.02 0.000084 28 3 mremap
0.02 0.000077 7 11 open
0.02 0.000066 5 14 close
[...]
------ ----------- ----------- --------- --------- ----------------
100.00 0.427920 10221 6 total
real 0m8.160s
user 0m0.115s
sys 0m0.961s
Wow, usque ad 8 seconds accelerationis! Nos omnes qui vocatus eiecit pretiosa getxattr()ac provocat capget() nimis evanuit, magna.
Sed adhuc sunt haec molestissima vocat lstat()Etsiβ¦
Quot flores tibi opus est?
Ergo propius aspectum cepimus LS_COLORS.
Primum hoc modo variabilis simpliciter erret:
$ echo $LS_COLORS rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36: $ unset LS_COLORS $ echo $LS_COLORS $ time ls --color=always $SCRATCH/dont | wc -l 10000 real 0m13.037s user 0m0.077s sys 0m1.092s
Quid est!?! Adhuc XIII seconds?
Evenit ut cum mauris varius LS_COLORS nisi unum ex elementis suis non definitur vel deest <type>=color:, constructo-in database per defaltam utitur et colore adhuc utitur. Si ergo vis colorizationem inactivare propter certum genus fasciculi, necesse est illud cum deprimi <type>=: aut <type> 00 in file DIR_COLORS.
Post multam probationem et errorem, inquisitionem nostram huc usque coartavimus;
EXEC 00
SETUID 00
SETGID 00
CAPABILITY 00quod scriptum est
LS_COLORS='ex=00:su=00:sg=00:ca=00:'
Hoc significat: non colorat lima per attributum. sed per partes neque per .
Nos accelerare ls
Et si hoc non feceris, tunc vocat lstat() evanescet et nunc res prorsus alia est;
$ export LS_COLORS='ex=00:su=00:sg=00:ca=00:'
$ time strace -c ls --color=always $SCRATCH/dont | wc -l
10000
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
63.02 0.002865 36 80 getdents
8.10 0.000368 12 30 mmap
5.72 0.000260 14 18 mprotect
3.72 0.000169 15 11 open
2.79 0.000127 13 10 read
[...]
------ ----------- ----------- --------- --------- ----------------
100.00 0.004546 221 6 total
real 0m0.337s
user 0m0.032s
sys 0m0.029s0,3 seconds in indice 10 tabularum, a record.
Occasus sursum Sherlock
Ex XIII seconds cum default occasus ad 13 seconds cum minor servandis LS_COLORS significat XL-complicare accelerationem ex absentia setuid / setgid et coloratis exsecutabile. Non tam magnum damnum.
Nempe hoc nunc in Sherlock configuratur pro sulum user.
Si colorantem reddere vis, simpliciter redire ad occasus defectus potes.
$ unset LS_COLORS
Sed tunc in directoriis cum multis documentis, cave ut capulus coquendam dum currit ls.
Source: www.habr.com