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Różnice między wybraną wersją a wersją aktualną.

@@ Linia 1: / Linia 1: @@
+<html>
+<style>
+.dokuwiki .wrap_column {margin:0}
+.wrap_column + .wrap_column {margin-left: 1em;}
+</style>
+</html>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c hello_world_v1.c>
+#include <unistd.h>
+int main() {
+  write(1, "Hello world!\n", 13);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c hello_world_v2.c>
+#include <string.h>
+#include <unistd.h>
+int main() {
+  const char *text = "Hello world!\n";
+  write(STDOUT_FILENO, text, strlen(text));
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c greeter_v1.c>
+#include <string.h>
+#include <unistd.h>
+int main() {
+  const char *text = "Podaj swoje imię: ";
+  write(STDOUT_FILENO, text, strlen(text));
+  char buffer[256];
+  int nameLength;
+  nameLength = read(0, buffer, 256);
+  text = "Witaj ";
+  write(STDOUT_FILENO, text, strlen(text));
+  write(STDOUT_FILENO, buffer, nameLength);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c greeter_v2.c>
+#include <string.h>
+#include <unistd.h>
+int main() {
+  const char *text = "Podaj swoje imię: ";
+  write(STDOUT_FILENO, text, strlen(text));
+  #define BUFFSIZE 256
+  char buffer[BUFFSIZE];
+  int nameLength;
+  nameLength = read(STDIN_FILENO, buffer, BUFFSIZE);
+  text = "Witaj ";
+  write(STDOUT_FILENO, text, strlen(text));
+  write(STDOUT_FILENO, buffer, nameLength);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c greeter_v3.c>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+int main() {
+  const char *text = "Podaj swoje imię: ";
+  write(STDOUT_FILENO, text, strlen(text));
+  int buffsize = 256;
+  char *buffer = malloc(buffsize);
+  int nameLength;
+  nameLength = read(STDIN_FILENO, buffer, buffsize);
+  text = "Witaj ";
+  write(STDOUT_FILENO, text, strlen(text));
+  write(STDOUT_FILENO, buffer, nameLength);
+  free(buffer);
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<code c stdlib_buffering.c>
+#include <stdio.h>
+#include <unistd.h>
+int main() {
+  printf("no");
+  write(1, "to", 2);
+  printf("wać\n");
+  printf("no");
+  write(1, "to", 2);
+  printf("wać\n");
+  return 0;
+}
+</code>
+Por. ''[[https://man7.org/linux/man-pages/man1/stdbuf.1.html|man stdbuf]]'' i funkcja ''[[https://en.cppreference.com/w/c/io/setbuf|setbuf]]''/''[[https://en.cppreference.com/w/c/io/setvbuf|setvbuf]]''.
+~~Zadanie.#~~
+Program zakłada że nie wystąpią błędy (obsługę błędów pokazuje kolejne zadanie).
+<WRAP group>
+<WRAP column>
+<code c data_txt_displayer.c>
+#include <fcntl.h>
+#include <unistd.h>
+int main() {
+  int fd = open("data.txt", O_RDONLY);
+  while (1) {
+    char buf[256];
+    int cnt = read(fd, buf, 256);
+    if (cnt <= 0)
+      break;
+    write(1, buf, cnt);
+  }
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c cat.c>
+#include <fcntl.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  for (int i = 1; i < argc; ++i) {
+    int fd = open(argv[i], O_RDONLY);
+    while (1) {
+      char buf[256];
+      int cnt = read(fd, buf, 256);
+      if (cnt <= 0)
+        break;
+      write(1, buf, cnt);
+    }
+    close(fd);
+  }
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c open_failure_reason_v1.c>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc < 2) {
+    fprintf(stderr, "No file name given!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR);
+  if (fd == -1) {
+    switch (errno) {
+    case ENOENT: fprintf(stderr, "\e[44m"); break;
+    case EACCES: fprintf(stderr, "\e[41m"); break;
+    case EISDIR: fprintf(stderr, "\e[42m"); break;
+    case ELOOP:  fprintf(stderr, "\e[46m"); break;
+    case ENXIO:  fprintf(stderr, "\e[45m"); break;
+    }
+    perror("Failed to open file");
+    fprintf(stderr, "\e[0m");
+    return 1;
+  }
+  printf("File successfully opened.");
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c open_failure_reason_v2.c>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc < 2) {
+    fprintf(stderr, "No file name given!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR);
+  if (fd == -1) {
+    int color =   errno == ENOENT ? 44
+                : errno == EACCES ? 41
+                : errno == EISDIR ? 42
+                : errno == ELOOP  ? 46
+                : errno == ENXIO  ? 45
+                                  : 0;
+    fprintf(stderr,
+      "Failed to open file: \e[%dm%s\e[0m.\n",
+      color, strerror(errno));
+    return 1;
+  }
+  printf("File successfully opened.");
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<code c cmp.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 3) { fprintf(stderr, "Wrong argument count!\n"); return 2; }
+  int a = open(argv[1], O_RDONLY);
+  if (a == -1) { perror("Opening the first file failed"); return 2; }
+  int b = open(argv[2], O_RDONLY);
+  if (b == -1) { perror("Opening the second file failed"); close(a); return 2; }
+  char bufA[256], bufB[256];
+  int cntA, cntB, rv;
+  while (1) {
+    cntA = read(a, bufA, 256);
+    cntB = read(b, bufB, 256);
+    if (cntA != cntB) {
+      printf("Files differ\n");
+      rv = 1; break;
+    }
+    if (memcmp(bufA, bufB, cntA)) {
+      printf("Files differ\n");
+      rv = 1; break;
+    }
+    if (cntA <= 0) {
+      printf("Files are identical\n");
+      rv = 0; break;
+    }
+  }
+  close(a);
+  close(b);
+  return rv;
+}
+</code>
+~~Zadanie.#~~
+<code c upper_lower.c>
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int src = open(argv[1], O_RDONLY);
+  if (src == -1) {
+    perror("Opening the source file failed");
+    return 1;
+  }
+  char *filename_buffer = malloc(strlen(argv[1]) + 3);
+  sprintf(filename_buffer, "%s_l", argv[1]);
+  int lower = open(filename_buffer, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+  if (lower == -1)
+    perror("Creating the lowercase variant failed");
+  sprintf(filename_buffer, "%s_u", argv[1]);
+  int upper = open(filename_buffer, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+  if (upper == -1)
+    perror("Creating the uppercase variant failed");
+  free(filename_buffer);
+  if (lower == -1 && upper == -1) {
+    close(src);
+    return 1;
+  }
+  char buf[256];
+  while (1) {
+    int cnt = read(src, buf, 256);
+    if (cnt <= 0)
+      break;
+    for (int i = 0; i < cnt; ++i)
+      buf[i] = tolower(buf[i]);
+    write(lower, buf, cnt);
+    for (int i = 0; i < cnt; ++i)
+      buf[i] = toupper(buf[i]);
+    write(upper, buf, cnt);
+  }
+  close(src);
+  close(lower);
+  close(upper);
+  return 0;
+}
+</code>
+~~Zadanie.#~~
+<code c last_bytes.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDONLY);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  int filesize = lseek(fd, 0, SEEK_END);
+  char buf[256];
+  printf("The file has %d bytes.\nThe last %d bytes are:\n",
+         filesize, filesize < 16 ? filesize : 16);
+  fflush(stdout);
+  if (filesize < 16)
+    lseek(fd, 0, SEEK_SET);
+  else
+    lseek(fd, -16, SEEK_CUR);
+  int cnt = read(fd, buf, 16);
+  close(fd);
+  write(1, buf, cnt);
+  return 0;
+}
+</code>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c uppercaser_v1.c>
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  while (1) {
+    char buf[256];
+    int cnt = read(fd, buf, 256);
+    if (cnt <= 0)
+      break;
+    for (int i = 0; i < cnt; ++i)
+      buf[i] = toupper(buf[i]);
+    lseek(fd, -cnt, SEEK_CUR);
+    write(fd, buf, cnt);
+  }
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c uppercaser_v2.c>
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int reader = open(argv[1], O_RDONLY);
+  if (reader == -1) {
+    perror("Opening the file for reading failed");
+    return 1;
+  }
+  int writer = open(argv[1], O_WRONLY);
+  if (writer == -1) {
+    perror("Opening the file for writing failed");
+    close(reader);
+    return 1;
+  }
+  while (1) {
+    char buf[256];
+    int cnt = read(reader, buf, 256);
+    if (cnt <= 0)
+      break;
+    for (int i = 0; i < cnt; ++i)
+      buf[i] = toupper(buf[i]);
+    write(writer, buf, cnt);
+  }
+  close(reader);
+  close(writer);
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c read_pos_write_pos.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  setvbuf(stdout, NULL, _IONBF, 0);
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  int cnt, pos;
+  char buf[16];
+  pos = lseek(fd, 0, SEEK_CUR);
+  printf("Pos upon opening: %d\n", pos);
+  cnt = read(fd, buf, 16);
+  printf("First 16 bytes: ");
+  write(1, buf, cnt);
+  pos = lseek(fd, 0, SEEK_CUR);
+  printf("\nPos before 16-byte write: %d\n",
+         pos);
+  cnt = write(fd, "Kilroy was here ", 16);
+  pos = lseek(fd, 0, SEEK_CUR);
+  printf("Pos after  16-byte write: %d\n",
+         pos);
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c read_pos_append_pos.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  setvbuf(stdout, NULL, _IONBF, 0);
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR | O_APPEND);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  int cnt, pos;
+  char buf[16];
+  pos = lseek(fd, 0, SEEK_CUR);
+  printf("Pos upon opening: %d\n", pos);
+  cnt = read(fd, buf, 16);
+  printf("First 16 bytes: ");
+  write(1, buf, cnt);
+  pos = lseek(fd, 0, SEEK_CUR);
+  printf("\nPos before 16-byte write: %d\n",
+         pos);
+  cnt = write(fd, "Kilroy was here ", 16);
+  pos = lseek(fd, 0, SEEK_CUR);
+  printf("Pos after  16-byte write: %d\n",
+         pos);
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<code c trim_to_one_line.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  int newSize = 0;
+  while (1) {
+    char buf[256];
+    int cnt = read(fd, buf, 256);
+    if (cnt <= 0) {
+      close(fd);
+      return 0;
+    }
+    char *nlPos = memchr(buf, '\n', cnt);
+    if (!nlPos) {
+      newSize += cnt;
+      continue;
+    }
+    newSize += nlPos - buf + 1;
+    break;
+  };
+  ftruncate(fd, newSize);
+  close(fd);
+  return 0;
+}
+</code>
+~~Zadanie.#~~
+<code c petabytes.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+const char *head = "    |\\/\\\n   / oo |\n\\\\_\\ T  /"
+"\n \\---|  \\\n    /   |\n    |   |\n    |   |\n\n\n\n";
+const char *tail = "\n\n\n\n\n\n    |   |\n    | A \\"
+"\n    || ||\\\\\n    || || \\\\\n    ww  ww  \\\n";
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDWR | O_CREAT | O_EXCL, 0644);
+  if (fd == -1) {
+    perror("Creating the file failed");
+    return 1;
+  }
+  ftruncate(fd, 4.5036e15);
+  write(fd, head, strlen(head));
+  lseek(fd, 0, SEEK_END);
+  write(fd, tail, strlen(tail));
+  close(fd);
+  return 0;
+}
+</code>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c duplicating_v1.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1],
+                O_WRONLY | O_TRUNC | O_CREAT,
+);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  close(1);
+  dup(fd);
+  close(fd);
+  system("date '+%F %T'");
+  write(STDOUT_FILENO, "Hello", 5);
+  printf(" world!\n");
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c duplicating_v2.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1],
+                O_WRONLY | O_TRUNC | O_CREAT,
+);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  dup2(fd, 1);
+  close(fd);
+  system("date '+%F %T'");
+  write(STDOUT_FILENO, "Hello", 5);
+  printf(" world!\n");
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>
+~~Zadanie.#~~
+<WRAP group>
+<WRAP column>
+<code c unlink.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDONLY);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  unlink(argv[1]);
+  write(1, "Reading and printing the file:\n",
+);
+  while (1) {
+    char buf[256];
+    int cnt = read(fd, buf, 256);
+    if (cnt <= 0)
+      break;
+    write(1, buf, cnt);
+  }
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+<WRAP column>
+<code c unlink_plus_stat.c>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stderr, "Wrong argument count!\n");
+    return 1;
+  }
+  int fd = open(argv[1], O_RDONLY);
+  if (fd == -1) {
+    perror("Opening the file failed");
+    return 1;
+  }
+  unlink(argv[1]);
+  char *buf = malloc(strlen(argv[1]) + 17);
+  sprintf(buf, "Executing stat %s\n", argv[1]);
+  write(1, buf, strlen(buf));
+  system(buf + 10);
+  struct stat sb;
+  fstat(fd, &sb);
+  sprintf(buf, "Link count: %zu\n", sb.st_nlink);
+  write(1, buf, strlen(buf));
+  write(1, "Reading and printing the file:\n",
+);
+  while (1) {
+    char buf[256];
+    int cnt = read(fd, buf, 256);
+    if (cnt <= 0)
+      break;
+    write(1, buf, cnt);
+  }
+  close(fd);
+  return 0;
+}
+</code>
+</WRAP>
+</WRAP>

Jan Kończak

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