[24] | 1 | /* Copyright (C) 2012 by Mattia Monga <mattia.monga@unimi.it> */
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| 2 | /* $Id$ */
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| 3 |
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| 4 | #include <stdio.h>
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| 5 | #include <stdlib.h>
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| 6 | #include <string.h>
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| 7 | #include <sys/types.h>
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| 8 | #include <sys/stat.h>
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| 9 | #include <fcntl.h>
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| 10 | #include <unistd.h>
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| 11 | #include <limits.h>
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| 12 |
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| 13 | void lsofd(const char* name){
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| 14 | int i;
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| 15 | for (i=0; i<_POSIX_OPEN_MAX; i++){
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| 16 | struct stat buf;
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| 17 | if (fstat(i, &buf) == 0){
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| 18 | printf("%s fd:%d i-node: %d\n", name, i, buf.st_ino);
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| 19 | }
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| 20 | }
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| 21 | }
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| 22 |
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| 23 | main(){
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| 24 | pid_t pid;
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| 25 | int f, off;
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| 26 | char string[] = "Hello, world!\n";
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| 27 |
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| 28 | lsofd("padre (senza figli)");
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| 29 | printf("padre (senza figli) pipe *\n");
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| 30 | f = open("provaxxx.dat", O_CREAT|O_WRONLY|O_TRUNC, S_IRWXU);
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| 31 | if (f == -1){
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| 32 | perror("pipe");
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| 33 | exit(1);
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| 34 | }
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| 35 | lsofd("padre (senza figli)");
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[26] | 36 | if (write(f, string, (strlen(string))) != (strlen(string)) ){
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[24] | 37 | perror("write");
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| 38 | exit(1);
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| 39 | }
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| 40 |
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| 41 | off = lseek(f, 0, SEEK_CUR);
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| 42 | printf("padre (senza figli) seek: %d\n", off);
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| 43 |
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| 44 | printf("padre (senza figli) fork *\n");
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| 45 | if ( (pid = fork()) < 0){
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| 46 | perror("fork");
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| 47 | exit(1);
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| 48 | }
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| 49 | if (pid > 0){
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| 50 | lsofd("padre");
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| 51 | printf("padre close *\n");
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| 52 | printf("padre write *\n");
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| 53 | off = lseek(f, 0, SEEK_CUR);
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| 54 | printf("padre seek prima: %d\n", off);
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| 55 | if (write(f, string, (strlen(string))) != (strlen(string)) ){
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| 56 | perror("write");
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| 57 | exit(1);
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| 58 | }
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| 59 | lsofd("padre");
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| 60 | off = lseek(f, 0, SEEK_CUR);
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| 61 | printf("padre seek dopo: %d\n", off);
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| 62 | exit(0);
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| 63 | }
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| 64 | else {
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| 65 | lsofd("figlio");
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| 66 | printf("figlio close *\n");
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| 67 | printf("figlio write *\n");
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| 68 | off = lseek(f, 0, SEEK_CUR);
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| 69 | printf("figlio seek prima: %d\n", off);
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| 70 | if (write(f, string, (strlen(string))) != (strlen(string)) ){
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| 71 | perror("write");
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| 72 | exit(1);
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| 73 | }
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| 74 | lsofd("figlio");
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| 75 | off = lseek(f, 0, SEEK_CUR);
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| 76 | printf("figlio seek dopo: %d\n", off);
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| 77 | exit(0);
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| 78 | }
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| 79 | }
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| 80 |
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| 81 | /* Local Variables: */
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| 82 | /* compile-command: "make -k " */
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| 83 | /* End: */
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