\u8a71\u8aaa\u67d0\u4e00\u5929\uff0c\u4e00\u4f4d\u540c\u4e8b\u767c\u73fe\u67d0\u500b\u5728 UNIX \u4e0a\u7528 C \u5beb\u7684\u7a0b\u5f0f\uff0c\u8dd1\u4e00\u9663\u5b50\u5f8c\u4f3c\u4e4e\u6703\u5403\u6389\u5f88\u591a\u786c\u789f\u7a7a\u9593\uff0c\u5403\u6389\u7684\u786c\u789f\u7a7a\u9593\u7528 du \u53bb\u7b97\u537b\u8ddf df \u7684\u7d50\u679c\u5dee\u7570\u5f88\u5927\uff0c\u800c\u4e14\u628a process \u505c\u6389\u5f8c\uff0c\u7a7a\u9593\u7adf\u7136\u53c8\u81ea\u52d5\u6062\u5fa9\u6b63\u5e38\u4e86<\/p>\n
\u6700\u5f8c\uff0c\u7528 fstat \u53bb\u4ed4\u7d30\u5206\u6790\uff0c\u7d42\u65bc\u627e\u5230\u539f\u56e0\uff1a<\/p>\n
\u5df2\u7d93\u958b\u555f\u7684\u6a94\u6848\uff0c\u5373\u4f7f\u958b\u555f\u4e2d\u88ab\u5f37\u5236\u780d\u6389(unlink)\uff0c\u5c0d\u539f file descriptor \u6301\u7e8c\u5beb\u5165\u7684\u90e8\u4efd\u4ecd\u6703\u7e7c\u7e8c\u4f54\u7528\u786c\u789f\u7a7a\u9593\uff0c\u5beb\u5f97\u8d8a\u591a\uff0c\u4f54\u7528\u7684\u7a7a\u9593\u4e5f\u8d8a\u591a<\/strong><\/p><\/blockquote>\n
\u5be6\u52d9\u4e0a\u6700\u5e38\u9047\u5230\u9019\u7a2e\u72c0\u6cc1\u7684\u5c31\u662f log rotation\uff0c\u5c24\u5176\u662f rotation \u5f8c\u7684\u820a LOG \u662f\u58d3\u7e2e\u904e\u7684\u60c5\u6cc1\u3002\u56e0\u70ba\u7d93\u904e gzip \u58d3\u7e2e\u904e\u5f8c\uff0c\u539f\u59cb\u7684 LOG \u6703\u88ab\u522a\u9664\uff0c\u53ea\u7559\u4e0b XXX.gz\u3002\u9019\u500b\u6642\u5019\u5982\u679c\u6c92\u6709\u4eba\u901a\u77e5\u539f\u4f86\u5beb LOG \u7684\u7a0b\u5f0f\u8981\u91cd\u65b0\u958b\u555f\u4e00\u6b21 LOG (\u91cd\u65b0\u5beb\u4e00\u500b\u6a94\u6848)\uff0c\u5c31\u6703\u5c0e\u81f4\u7a0b\u5f0f\u5728\u4e0d\u77e5\u60c5\u72c0\u6cc1\u4e0b\u7e7c\u7e8c\u5beb LOG\uff0c\u7136\u5f8c\u7a7a\u9593\u5c31\u83ab\u540d\u5176\u5999\u88ab\u7528\u6389\u4e86\uff01<\/p>\n
\u4f8b\u5982 FreeBSD<\/a> \u4e0b\u5c08\u9580\u4f5c log rotation \u7684 newsyslog<\/a> \u8a2d\u5b9a\u6a94 (newsyslog.conf<\/a>) \u5c31\u6709\u500b\u6b04\u4f4d\u53ef\u4ee5\u8a2d\u5b9a\u5728 log rotation \u5f8c\u9001\u4e00\u500b signal \u7d66 process\uff0c\u800c apache (httpd) \u5c31\u63a5\u53d7 SIGUSR1 \u4f86\u7576\u4f5c\u91cd\u65b0\u958b\u555f LOG \u6a94\u6848\u7684\u8a0a\u865f\uff08\u4e8b\u5be6\u4e0a\u5c0d apache \u800c\u8a00\u662f graceful restart\uff09\u3002\u5f88\u591a\u4eba\u4ee5\u70ba\u9019\u53ea\u662f\u70ba\u4e86\u8b93 LOG \u80fd\u7e7c\u7e8c\u5beb\u4e0d\u6703\u6f0f\u6389\uff0c\u4f46\u5176\u5be6\u66f4\u91cd\u8981\u7684\u662f\uff1a\u5982\u679c\u4e0d\u9019\u9ebc\u4f5c\uff0c\u4f60\u7684\u786c\u789f\u53ef\u80fd\u5f88\u5feb\u5c31\u7206\u6389\u5566…<\/p>\n
\u6211\u5011\u53ef\u4ee5\u5beb\u500b\u7c21\u55ae\u7684\u7a0b\u5f0f\u4f86\u6e2c\u8a66\u4e00\u4e0b\u9019\u7a2e\u72c0\u6cc1\uff1a<\/p>\n
\r\n#include\r\n#include \r\nint main()\r\n{\r\n int fd, i;\r\n char cmd[32], buf[1024];\r\n memset( buf, 0, 1024);\r\n snprintf(cmd,sizeof(cmd),\"df .\");\r\n\r\n printf(\"==> open file for write and delete it ...\\n\");\r\n fd = open( \"test-file.log\", O_CREAT|O_WRONLY|O_TRUNC );\r\n unlink(\"test-file.log\");\r\n system(cmd);\r\n\r\n printf(\"\\n==> write 100MB to file ...\\n\");\r\n for( i = 0 ; i < 1000*100 ; i++ )\r\n write( fd, buf, 1024);\r\n system(cmd);\r\n\r\n printf(\"\\n==> close file ...\\n\");\r\n close(fd);\r\n system(cmd);\r\n}\r\n<\/pre>\n \u9996\u5148\uff0c\u9019\u500b\u5c0f\u7a0b\u5f0f\u6703\u5148\u958b\u555f\u4e00\u500b\u6a94\u6848\uff0c\u7136\u5f8c\u99ac\u4e0a\u780d\u6389\u5b83\uff08\u4f46\u5148\u4e0d\u95dc\u9589\u6a94\u6848\uff09\uff0c\u63a5\u4e0b\u4f86\u57f7\u884c “df .” \u4f86\u67e5\u770b\u76ee\u524d\u786c\u789f\u7528\u91cf\u3002\u7b2c\u4e8c\u6b65\u9a5f\u662f\u5beb\u5165100MB\u7684\u5783\u573e\u8cc7\u6599\u5230\u9019\u500b\u5df2\u958b\u555f\u7684\u6a94\u6848(file descriptor)\u4e2d\uff0c\u7136\u5f8c\u518d\u57f7\u884c “df .” \u4f86\u53d6\u5f97\u786c\u789f\u7528\u91cf\u3002\u6700\u5f8c\u95dc\u9589\u6a94\u6848\u5f8c\uff0c\u518d\u57f7\u884c\u4e00\u6b21 “df .”\u3002\u57f7\u884c\u7d50\u679c\u5982\u4e0b\uff1a<\/p>\n
\r\n==> open file for write and delete it ...\r\nFilesystem 1K-blocks Used Avail Capacity Mounted on\r\n\/dev\/ad8s1d 144520482 28011428<\/u> 104947416 21% \/home\r\n\r\n==> write 100MB to file ...\r\nFilesystem 1K-blocks Used Avail Capacity Mounted on\r\n\/dev\/ad8s1d 144520482 28111508<\/u> 104847336 21% \/home\r\n\r\n==> close file ...\r\nFilesystem 1K-blocks Used Avail Capacity Mounted on\r\n\/dev\/ad8s1d 144520482 28011428<\/u> 104947416 21% \/home\r\n<\/pre>\n\u6211\u5011\u53ef\u4ee5\u770b\u5230\u7a0b\u5f0f\u5beb\u4e86100MB\u4e4b\u5f8c\uff0c\u7a7a\u9593\u771f\u7684\u88ab\u4f54\u6389\u4e86\uff0c\u5373\u4f7f\u6211\u5011\u5df2\u7d93\u522a\u9664\u9019\u500b\u6a94\u6848\uff0c\u4e14\u5f9e\u76ee\u9304\u7684\u6a94\u6848\u5217\u8868\u4e2d\u7121\u6cd5\u76f4\u63a5\u770b\u5230\u9019\u500b\u6a94\u6848\u4e86\u3002\u800c\u7576\u88ab\u958b\u555f\u7684\u6a94\u6848\u95dc\u6389\u5f8c\uff0c\u9019\u4e9b\u7a7a\u9593\u4e5f\u7acb\u5373\u88ab\u91cb\u653e\u56de\u4f86\u4e86<\/p>\n
\u63a5\u4e0b\u4f86\u6211\u5011\u628a\u7a0b\u5f0f\u4e2d\u7684 df \u6539\u6210 fstat\uff0c\u53ef\u4ee5\u66f4\u6e05\u695a\u770b\u5230\u72c0\u6cc1<\/p>\n
\r\n snprintf(cmd,sizeof(cmd),\"fstat -f -p %d .\", getpid());\r\n<\/pre>\n\u9019\u662f\u6700\u5f8c\u7684\u7d50\u679c\uff1a<\/p>\n
\r\n==> open file for write and delete it ...\r\nUSER CMD PID FD MOUNT INUM MODE SZ|DV R\/W\r\ncdsheen a.out 91475 wd \/home 12694528 drwxr-xr-x 2048 r\r\ncdsheen a.out 91475 text \/home 12694672 -rwxr-xr-x 7910 r\r\ncdsheen a.out 91475 3 \/home 12694673 ----r-x--x 0 w\r\n\r\n==> write 100MB to file ...\r\nUSER CMD PID FD MOUNT INUM MODE SZ|DV R\/W\r\ncdsheen a.out 91475 wd \/home 12694528 drwxr-xr-x 2048 r\r\ncdsheen a.out 91475 text \/home 12694672 -rwxr-xr-x 7910 r\r\ncdsheen a.out 91475 3 \/home 12694673 ----r-x--x 102400000<\/u> w\r\n\r\n==> close file ...\r\nUSER CMD PID FD MOUNT INUM MODE SZ|DV R\/W\r\ncdsheen a.out 91475 wd \/home 12694528 drwxr-xr-x 2048 r\r\ncdsheen a.out 91475 text \/home 12694672 -rwxr-xr-x 7910 r\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"\u8a71\u8aaa\u67d0\u4e00\u5929\uff0c\u4e00\u4f4d\u540c\u4e8b\u767c\u73fe\u67d0\u500b\u5728 UNIX \u4e0a\u7528 C 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[…]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[9,10],"tags":[19,22,20,21,18],"class_list":["post-65","post","type-post","status-publish","format-standard","hentry","category-os","category-language","tag-disk","tag-fstat","tag-log","tag-rotation","tag-storage"],"views":4841,"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pubdi-13","jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":84,"url":"https:\/\/dada.tw\/blog\/2008\/04\/18\/84\/","url_meta":{"origin":65,"position":0},"title":"Bypass the 2GB file size limit on 32-bit 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