{"id":38,"date":"2019-08-01T22:56:24","date_gmt":"2019-08-01T20:56:24","guid":{"rendered":"http:\/\/linuxboxen2.dk\/?p=38"},"modified":"2019-08-01T22:56:24","modified_gmt":"2019-08-01T20:56:24","slug":"program-pid-hvad-er-det","status":"publish","type":"post","link":"https:\/\/www.linuxboxen.dk\/?p=38","title":{"rendered":"Program PID hvad er det ?."},"content":{"rendered":"\n

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https:\/\/www.bogotobogo.com\/Linux\/linux_process_and_signals.php<\/a><\/p>\n\n

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Vi f\u00e5r f\u00f8lgende svar p\u00e5 ps -ef<\/span><\/span><\/p>\n\n

\nUID        PID  PPID  C STIME TTY          TIME CMD\nroot         1<\/font>     0  0  2010 ?        00:01:48 init<\/font> \nroot     21033     1  0 Apr04 ?        00:00:39 crond\nroot     24765     1  0 Apr08 ?        00:00:01 \/usr\/sbin\/httpd<\/pre>\n\n
Hver proces tildeles et unikt nummer, proces identifikator (PID).<\/span> Det er et helt tal mellem 2 og 32.768.<\/span> N\u00e5r en proces startes, genstarter tallene fra 2, og nummeret 1 er typisk forbeholdt init-processen som vist i ovenst\u00e5ende eksempel.<\/span> Processen # 1 styrer andre processer.<\/span>
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\nN\u00e5r vi k\u00f8rer et program, bliver koden, der udf\u00f8res, gemt i en diskfil.<\/span> Generelt kan en Linux-proces ikke skrive til hukommelsesomr\u00e5det.<\/span> Omr\u00e5det er beregnet til at holde programkoden, s\u00e5 koden kan l\u00e6gges i hukommelsen som skrivebeskyttet (s\u00e5 den kan sikkert deles).<\/span><\/span><\/p>\n\n
Systembibliotekerne kan ogs\u00e5 deles.<\/span> Derfor er der kun brug for en kopi af printf () i hukommelsen, selvom der er mange programmer, der kalder det.<\/span>
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\nN\u00e5r vi k\u00f8rer to programmer, er der variabler, der er unikke for hvert program, i mods\u00e6tning til de delte biblioteker, er disse i separat dataplads for hver proces, og de kan normalt ikke deles.<\/span> Med andre ord har en proces sin egen stakplads, der anvendes til lokale variabler.<\/span> Det har ogs\u00e5 sine egne milj\u00f8variabler, som vedligeholdes af hver proces.<\/span> En proces skal ogs\u00e5 have sin egen programt\u00e6ller, en oversigt over, hvor den er kommet i dens udf\u00f8relse (execution thread – mere p\u00e5 Linux pthread).<\/span><\/span><\/p>\n\n
Proces tabel<\/span>
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\nProcessetabellen beskriver alle de processer, der aktuelt er indl\u00e6st.<\/span> PS-kommandoen viser processerne.<\/span> Som standard viser det kun processer, der opretholder forbindelse til en terminal, en konsol, en serielinie eller en pseudoterminal.<\/span> Andre processer, der kan k\u00f8re uden kommunikation med en bruger p\u00e5 en terminal, er systemprocesser, som Linux administrerer delte ressourcer.<\/span> For at se alle processer bruger vi -e mulighed og -f for at f\u00e5 fuld information (ps -ef).<\/span><\/span><\/p>\n\n
Systemprocesser<\/span>
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\nHer er STAT-output fra ps:<\/span><\/span><\/p>\n\n
\n$ ps -ax<\/font>\n  PID TTY      STAT<\/font>   TIME COMMAND\n    1 ?        Ss     1:48 init [3]\n    2 ?        S<     0:03 [migration\/0]\n    3 ?        SN     0:00 [ksoftirqd\/0]\n ....\n 2981 ?        S<sl  10:14 auditd\n 2983 ?        S<sl   3:43 \/sbin\/audispd\n ....\n 3428 ?        SLs    0:00 ntpd -u ntp:ntp -p \/var\/run\/ntpd.pid -g\n 3464 ?        Ss     0:00 rpc.rquotad\n 3508 ?        S<     0:00 [nfsd4]\n ....\n 3812 tty1     Ss+    0:00 \/sbin\/mingetty tty1\n 3813 tty2     Ss+    0:00 \/sbin\/mingetty tty2\n 3814 tty3     Ss+    0:00 \/sbin\/mingetty tty3\n 3815 tty4     Ss+    0:00 \/sbin\/mingetty tty4\n.....\n19874 pts\/1    R+     0:00 ps -ax\n19875 pts\/1    S+     0:00 more\n21033 ?        Ss     0:39 crond\n24765 ?        Ss     0:01 \/usr\/sbin\/httpd\n<\/pre>\n\n
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\"process<\/p>\n\n","protected":false},"excerpt":{"rendered":"
  https:\/\/www.bogotobogo.com\/Linux\/linux_process_and_signals.php   Vi f\u00e5r f\u00f8lgende svar p\u00e5 ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 2010 ? 00:01:48 init root 21033 1 0 Apr04 ? 00:00:39 crond root 24765 1 0 Apr08 ? 00:00:01 \/usr\/sbin\/httpd Hver proces tildeles et unikt nummer, proces identifikator (PID). Det er et helt […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[2],"tags":[],"class_list":["post-38","post","type-post","status-publish","format-standard","hentry","category-tips"],"a3_pvc":{"activated":false,"total_views":0,"today_views":0},"_links":{"self":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/38","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=38"}],"version-history":[{"count":0,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/38\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=38"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=38"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=38"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}