X-Git-Url: http://svarog.pmf.uns.ac.rs/gitweb/?p=os2skripta.git;a=blobdiff_plain;f=skripta-os2.tex;h=57a5b151641730279501c2405fa86cb9999005ef;hp=48ce00bad10e288a786601477096264a2f042318;hb=5a7e8d6b69325e5d9c135343589a380459e819a2;hpb=0e8e29487850f177c24117f8bc6cfb74edab92b9

diff --git a/skripta-os2.tex b/skripta-os2.tex
index 48ce00b..57a5b15 100644
--- a/skripta-os2.tex
+++ b/skripta-os2.tex
@@ -372,13 +372,6 @@ kraju i zatvara otvoreni direktorijum. Bitno je zatvarati otvorene
 resurse jer je moguće da sistem odbije da otvori novi ako ih
 proces već ima previše otvorenih.
 
-Kada imamo imena stavki iz direktorijuma o njima možemo dobiti više
-informacija \kod{stat}. Ona prima dva argumenta, prvi je \emph{puna}
-putanja do fajla, a drugi je pokazivač na strukturu u koju će komanda
-upisati podatke. Obratiti pažnju da zbog ovoga struktura već mora
-postojati u memoriji, ili kao lokalna promenljiva odgovarajućeg
-slogovnog tipa, ili dinamički alocirana korišćenjem pokazivača na nju.
-
 Budući da su u pitanju sistemski pozivi niskog nivoa, veličine tipova
 su nažalost promenljive i mogu zavisiti od konkretnog operativnog
 sistema, a naročito utiče da li je u pitanju~32--bitni, ili~64--bitni
@@ -387,25 +380,146 @@ Prva je testirana na Lubuntu 11.10 i 12.04 32bit, a druga je testirana
 na Kubuntu 11.10 i 12.10 64bit.
 
 \begin{codeblock}
-DEFINITION MODULE FOR "C" Lib32;
+DEFINITION MODULE FOR "C" libdir;
+
   FROM SYSTEM IMPORT 
     ADDRESS, BYTE;
-  EXPORT UNQUALIFIED opendir, readdir, closedir, stat, 
-    PDir, DirEnt, PDirEnt, Stat, PStat, PInt;
+
+  EXPORT UNQUALIFIED opendir, readdir, closedir, PDir, DirEnt, PDirEnt;
 \end{codeblock}
-\begin{minipage}{0.5\textwidth}
+\begin{minipage}{0.45\textwidth}
 \begin{codeblock}
 (* types for 32 bit *)
   TYPE
     PDir = ADDRESS;
     DirEnt = RECORD
-         ino: INTEGER;
-         off: INTEGER;
-         reclen: SHORTCARD;
-         type: BYTE;
-         name: ARRAY [0..255] OF CHAR;
+       ino: INTEGER;
+       off: INTEGER;
+       reclen: SHORTCARD;
+       type: BYTE;
+       name: ARRAY [0..255] OF CHAR;
+    END;
+    PDirEnt = POINTER TO DirEnt;
+ \end{codeblock}
+\end{minipage}
+\begin{minipage}{0.45\textwidth}
+\begin{codeblock}[frame=single,frameround=tttt]
+(* types for 64 bit *)
+  TYPE
+    PDir = ADDRESS;
+    DirEnt = RECORD
+       ino: LONGINT;
+       off: LONGINT;
+       reclen: SHORTCARD;
+       type: BYTE;
+       name: ARRAY [0..255] OF CHAR;
     END;
     PDirEnt = POINTER TO DirEnt;
+\end{codeblock}
+\end{minipage}
+\begin{codeblock}
+  PROCEDURE opendir(name: ARRAY OF CHAR): PDir;
+  PROCEDURE readdir(dirp: PDir): PDirEnt;
+  PROCEDURE closedir(dirp: PDir): [INTEGER];
+
+END libdir.
+\end{codeblock}
+
+\begin{codeblock}
+MODULE Zad3;
+
+FROM StrIO IMPORT
+  WriteString, WriteLn;
+FROM NumberIO IMPORT
+  WriteInt;
+FROM Args IMPORT
+  Narg, GetArg;
+  FROM libdir IMPORT
+  opendir, readdir, closedir, PDir, PDirEnt;
+FROM errno IMPORT
+  geterrno;
+
+TYPE
+  String = ARRAY [0..1023] OF CHAR;
+
+VAR
+  Putanja: String;
+  n, i: INTEGER;
+  ok: BOOLEAN;
+
+PROCEDURE Listaj(Ime: ARRAY OF CHAR);
+VAR
+  dir: PDir;
+  entry: PDirEnt;
+  c: INTEGER;
+BEGIN
+  WriteString("Folder "); WriteString(Ime); WriteLn;
+  dir:= opendir(Ime);
+  IF dir = NIL THEN
+    WriteString("  Greska broj "); WriteInt(geterrno(), 0); WriteString("."); WriteLn();
+    WriteString("  Ne mogu da otvorim direktorijum."); WriteLn();
+  ELSE
+    entry:= readdir(dir);
+    WHILE entry # NIL DO
+      IF entry^.name[0] # "." THEN
+        WriteString("  "); WriteString(entry^.name); WriteLn;
+      END;
+      entry:= readdir(dir);
+    END;
+    c:= closedir(dir);
+    IF c = -1 THEN
+      WriteString("  Greska broj "); WriteInt(geterrno(), 0); WriteString("."); WriteLn();
+      WriteString("  Ne mogu da zatvorim direktorijum."); WriteLn();
+    END;
+  END;
+END Listaj;
+
+BEGIN
+  n:= Narg();
+  FOR i:= 1 TO n - 1 DO
+    ok:= GetArg(Putanja, i);
+    WriteLn;
+    Listaj(Putanja);
+  END;
+  WriteLn;
+END Zad3.
+\end{codeblock}
+
+Kada imamo imena stavki iz direktorijuma o njima možemo dobiti više
+informacija koristeći sistemski poziv \kod{stat}. On prima dva
+argumenta, prvi je \emph{puna} putanja do fajla, a drugi je pokazivač
+na strukturu u koju će komanda upisati podatke. Obratiti pažnju da
+zbog ovoga struktura već mora postojati u memoriji, ili kao lokalna
+promenljiva odgovarajućeg slogovnog tipa, ili dinamički alocirana
+korišćenjem pokazivača na nju.
+
+Linux i mnogi drugi srodni sistemi za internu prezentaciju vremena
+koriste broj sekundi od početka ``epohe'', odnosno od prvog januara
+1970 godine. Za konverziju u klasičnije mere vremena se može koristiti
+poziv \kod{localtime}.
+
+\begin{codeblock}
+DEFINITION MODULE FOR "C" LibStat32;
+  FROM SYSTEM IMPORT 
+    ADDRESS, BYTE;
+  EXPORT UNQUALIFIED stat, localtime,
+    Stat, PStat, Tm, PTm, PInt,
+    fifo, character, directory, block, regular, network, link, socket;
+
+  CONST
+    fifo      =  1;
+    character =  2;
+    directory =  4;
+    block     =  6;
+    regular   =  8;
+    network   =  9;
+    link      = 10;
+    socket    = 12;
+\end{codeblock}
+\begin{minipage}{0.45\textwidth}
+\begin{codeblock}
+(* types for 32 bit *)
+  TYPE
     Stat = RECORD
          dev: LONGINT;
          ino: LONGINT;
@@ -428,15 +542,6 @@ DEFINITION MODULE FOR "C" Lib32;
 \begin{codeblock}[frame=single,frameround=tttt]
 (* types for 64 bit *)
   TYPE
-    PDir = ADDRESS;
-    DirEnt = RECORD
-         ino: LONGINT;
-         off: LONGINT;
-         reclen: SHORTCARD;
-         type: BYTE;
-         name: ARRAY [0..255] OF CHAR;
-    END;
-    PDirEnt = POINTER TO DirEnt;
     Stat = RECORD
          dev: LONGINT;
          ino: LONGINT;
@@ -456,18 +561,22 @@ DEFINITION MODULE FOR "C" Lib32;
   \end{codeblock}
 \end{minipage}
 \begin{codeblock}
-    PStat = POINTER TO Stat;
+    Tm = RECORD
+             sec, min, hour,
+             mday, mon, year,
+             wday, yday, isdst: INTEGER;
+         END;
+    PTm = POINTER TO Tm;
     PInt = POINTER TO INTEGER;
 
-  PROCEDURE opendir(name: ARRAY OF CHAR): PDir;
-  PROCEDURE readdir(dirp: PDir): PDirEnt;
-  PROCEDURE closedir(dirp: PDir): [INTEGER];
   PROCEDURE stat(path: ARRAY OF CHAR; buf: PStat): [INTEGER];
-END Lib32.
+  PROCEDURE localtime(time: PInt): PTm;
+
+END LibStat32.
 \end{codeblock}
 
 \begin{codeblock}
-MODULE Zad5;
+MODULE Zad4;
 
 FROM SYSTEM IMPORT
   ADR;
@@ -479,8 +588,9 @@ FROM StrLib IMPORT
   StrLen, StrConCat;
 FROM Args IMPORT
   Narg, GetArg;
-FROM Lib32 IMPORT
-  opendir, readdir, closedir, stat, PDir, PDirEnt, Stat;
+FROM LibStat32 IMPORT
+  stat, localtime, Stat, PTm;
+IMPORT LibStat32;
 FROM errno IMPORT
   geterrno;
 
@@ -492,48 +602,104 @@ VAR
   n, i: INTEGER;
   ok: BOOLEAN;
 
-PROCEDURE Listaj(Ime: ARRAY OF CHAR);
+PROCEDURE WriteMode(mode: INTEGER);
+
+  PROCEDURE WriteType(type: INTEGER);
+  BEGIN
+    IF type = lib32.fifo THEN
+      WriteString("f");
+    ELSIF type = lib32.character THEN
+      WriteString("c");
+    ELSIF type = lib32.directory THEN
+      WriteString("d");
+    ELSIF type = lib32.block THEN
+      WriteString("b");
+    ELSIF type = lib32.regular THEN
+      WriteString("-");
+    ELSIF type = lib32.network THEN
+      WriteString("n");
+    ELSIF type = lib32.link THEN
+      WriteString("l");
+    ELSIF type = lib32.socket THEN
+      WriteString("s");
+    ELSE
+      WriteString("?");
+    END;
+  END WriteType;
+
+  PROCEDURE WriteRWX(triplet: INTEGER);
+  BEGIN
+    IF ((triplet DIV 4) MOD 2) # 0 THEN
+      WriteString("r");
+    ELSE
+      WriteString("-");
+    END;
+    IF ((triplet DIV 2) MOD 2) # 0 THEN
+      WriteString("w");
+    ELSE
+      WriteString("-");
+    END;
+    IF (triplet MOD 2) # 0 THEN
+      WriteString("x");
+    ELSE
+      WriteString("-");
+    END;
+  END WriteRWX;
+
+BEGIN
+  WriteType((mode DIV 4096) MOD 16);
+  WriteRWX(mode DIV 64);
+  WriteRWX(mode DIV 8);
+  WriteRWX(mode);
+END WriteMode;
+
+PROCEDURE WriteTime(time: LONGINT);
 VAR
-  dir: PDir;
-  entry: PDirEnt;
-  info: Stat;
-  c: INTEGER;
-  Len: CARDINAL;
-  Putanja: String;
+  tm: PTm;
 BEGIN
-  dir:= opendir(Ime);
-  IF dir = NIL THEN
-    WriteString("Folder "); WriteString(Ime); WriteLn;
-    WriteString("  Greska broj "); WriteInt(geterrno(), 0); WriteString("."); WriteLn();
-    WriteString("  Ne mogu da otvorim direktorijum."); WriteLn();
-  ELSE
-    Len:= StrLen(Ime);
-    IF Ime[Len - 1] # "/" THEN
-      StrConCat(Ime, "/", Ime);
+  tm:= localtime(ADR(time));
+  IF tm # NIL THEN
+    WriteInt(tm^.year + 1900, 0);
+    WriteString("-");
+    IF tm^.mon < 9 THEN
+      WriteString("0");
     END;
-    WriteString("Folder "); WriteString(Ime); WriteLn;
-    entry:= readdir(dir);
-    WHILE entry # NIL DO
-      IF entry^.name[0] # "." THEN
-        StrConCat(Ime, entry^.name, Putanja);
-        c:= stat(Putanja, ADR(info));
-        WriteString("  ");
-        IF c = -1 THEN
-          WriteString("?    ? KB");
-        ELSE
-          WriteInt(info.nlink, 3);
-          WriteInt((info.size + 512) DIV 1024, 5); WriteString(" KB ");
-        END;
-        WriteString(" "); WriteString(entry^.name); WriteLn;
-      END;
-      entry:= readdir(dir);
+    WriteInt(tm^.mon + 1, 0);
+    WriteString("-");
+    IF tm^.mday < 10 THEN
+      WriteString("0");
     END;
-    c:= closedir(dir);
-    IF c = -1 THEN
-      WriteString("  Greska broj "); WriteInt(geterrno(), 0); WriteString("."); WriteLn();
-      WriteString("  Ne mogu da zatvorim direktorijum."); WriteLn();
+    WriteInt(tm^.mday, 0);
+    WriteString(" ");
+    IF tm^.hour < 10 THEN
+      WriteString("0");
+    END;
+    WriteInt(tm^.hour, 0);
+    WriteString(":");
+    IF tm^.hour < 10 THEN
+      WriteString("0");
     END;
+    WriteInt(tm^.min, 0);
+  ELSE
+    WriteString("??:??");
   END;
+END WriteTime;
+
+PROCEDURE Listaj(Putanja: ARRAY OF CHAR);
+VAR
+  info: Stat;
+  c: INTEGER;
+BEGIN
+  c:= stat(Putanja, ADR(info));
+  IF c = -1 THEN
+    WriteString("??????????  ?    ? KB ????-??-?? ??:??");
+  ELSE
+    WriteMode(info.mode);
+    WriteInt(info.nlink, 3);
+    WriteInt((info.size + 512) DIV 1024, 5); WriteString(" KB ");
+    WriteTime(info.atime);
+  END;
+  WriteString(" "); WriteString(Putanja); WriteLn;
 END Listaj;
 
 BEGIN
@@ -544,7 +710,7 @@ BEGIN
     Listaj(Putanja);
   END;
   WriteLn;
-END Zad5.
+END Zad4.
 \end{codeblock}
 
 \subsection{Stvaranje novih procesa}
@@ -634,14 +800,14 @@ END;
 \begin{minipage}{0.4\textwidth}
 \begin{tikzpicture}
 [proc/.style={circle,draw}]
-\def \n {5}
-\node[proc] (1) at (0,0) {1};
-\foreach \s in {2,...,\n}
+\def \n {3}
+\node[proc] (top) at (0,0) {0..4};
+\foreach \s in {0,...,\n}
 {
-  \node[proc] (\s) at (-3.5+\s,-2) {\s};
+  \node[proc] (\s) at (-1.5+\s,-2) {\s};
 }
-\foreach \s in {2,...,\n} {
-  \draw [->] (1) to (\s);
+\foreach \s in {0,...,\n} {
+  \draw [->] (top) to (\s);
 }
 \end{tikzpicture}
 \end{minipage}
@@ -667,14 +833,18 @@ END;
 \begin{minipage}{0.4\textwidth}
 \begin{tikzpicture}
 [proc/.style={circle,draw},
-level 1/.style={sibling distance=20mm,level distance=10mm},
-level 2/.style={sibling distance=10mm,font=\scriptsize}
+level 1/.style={sibling distance=28mm,level distance=10mm},
+level 2/.style={sibling distance=14mm,font=\scriptsize},
+level 3/.style={sibling distance=6mm,font=\tiny}
 ]
-\node[proc] (root) {0}
-child[->] foreach \x in {1,2} {node[proc] {\x}
-  child foreach \y in {1,2} {node[proc] {\x-\y}
-    }};
-
+\node[proc] (root) {1-0}
+child[->] foreach \x in {0,1} {node[proc] {1-\x}
+  child foreach \y in {0,1} {node[proc] {2-\y}
+    child foreach \z in {0,1} {node[proc] {3-\z}
+    }}};
+
+\node[text width=0.9\textwidth] (desc) at (0,-4) {maxdubina=4, potrebnodece=2, 
+čvorovi prikazuju vrednosti pri kreiranju};
 \end{tikzpicture}
 \end{minipage}
 
@@ -743,6 +913,13 @@ sudo apt-get source gm2
 
 Videti Glavu~\ref{g-prvi-program} za primer kompajliranja programa.
 
+\paragraph{Napomena:} Prilikom unapredjivanja Linux distribucije na
+sledeću verziju (npr. 13.10 na 14.04) se standardno onemogućavaju
+dodati izvori softvera i potrebno ih je ručno ponovo upaliti.  Ovo se
+može uraditi otvoranjem \kod{/etc/apt/sources.list} i uklonjanjem
+``\#'' sa početka redova koje želimo da koristimo ponovo ili
+korišćenjem adekvatnih vizuelnih alata.
+
 \subsection{Problem: nedostaje ``ctli.o'' i/ili još neki fajlovi}
 
 Pri pokušaju kompajliranja se na nekim sistemima može desiti da