Author: gahr (ports committer) Date: Tue Jun 13 12:35:01 2017 New Revision: 319897 URL: https://svnweb.freebsd.org/changeset/base/319897
Log: Improve yes' throughput On my system, this brings up the throughput from ~20 to ~600 MiB/s. Inspired by: https://www.reddit.com/r/unix/comments/6gxduc/how_is_gnu_yes_so_fast/ Reviewed by: cognet Approved by: cognet Modified: head/usr.bin/yes/yes.c Modified: head/usr.bin/yes/yes.c ============================================================================== --- head/usr.bin/yes/yes.c Tue Jun 13 12:07:18 2017 (r319896) +++ head/usr.bin/yes/yes.c Tue Jun 13 12:35:01 2017 (r319897) @@ -44,20 +44,42 @@ static const char rcsid[] = "$FreeBSD$"; #include <capsicum_helpers.h> #include <err.h> #include <stdio.h> +#include <string.h> +#include <unistd.h> int main(int argc, char **argv) { + char buf[8192]; + char y[2] = { 'y', '\n' }; + char * exp = y; + size_t buflen = 0; + size_t explen = sizeof(y); if (caph_limit_stdio() < 0 || (cap_enter() < 0 && errno != ENOSYS)) err(1, "capsicum"); if (argc > 1) - while (puts(argv[1]) != EOF) - ; - else - while (puts("y") != EOF) - ; + { + exp = argv[1]; + explen = strlen(exp) + 1; + exp[explen - 1] = '\n'; + } + + if (explen <= sizeof(buf)) + { + while (buflen < sizeof(buf) - explen) + { + memcpy(buf + buflen, exp, explen); + buflen += explen; + } + exp = buf; + explen = buflen; + } + + while (write(STDOUT_FILENO, exp, explen) > 0) + ; + err(1, "stdout"); /*NOTREACHED*/ } _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
