Last login: Tue Apr 11 17:11:44 2017 from 10.31.122.154
[cs50@flume ~]$ cd demo
[cs50@flume ~/demo]$ ls
names0.c  names2.c  names4.c  names6.c	readlinep.c@  students.txt
names1.c  names3.c  names5.c  names7.c	readlinep.h@
[cs50@flume ~/demo]$ cat names2.c 
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names [filename]
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "freadline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  const int maxLength = 50;  // maximum length of a name (minus 2)
  char names[maxNames][maxLength];
  FILE *fp;		      // input file
  int n = 0;		      // number of names read

  // validate arguments and open input file
  if (argc == 1) {
    fp = stdin;
  } else if (argc == 2) {
    fp = fopen(argv[1], "r");
    if (fp == NULL) {
      fprintf(stderr, "%s cannot open file '%s'\n", argv[0], argv[1]);
      exit (2);
    } 
  } else {
    fprintf(stderr, "usage: %s [filename]\n", argv[0]);
    exit (1);
  }

  // read the list of names
  for (n = 0; n < maxNames && !feof(fp); ) {
    if (freadLine(fp, names[n], maxLength)) {
      n++; // only increment if no error
    }
  }

  fclose(fp);

  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
[cs50@flume ~/demo]$ cp names2.c names.c
[cs50@flume ~/demo]$ emacs !$
emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  const int maxLength = 50;  // maximum length of a name (minus 2)
  char names[maxNames][maxLength];
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(fp); ) {
    if (readLine(names[n], maxLength)) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
names.c:15:22: fatal error: readline.h: No such file or directory
 #include "readline.h"
                      ^
compilation terminated.
[cs50@flume ~/demo]$ cp ~cs50/examples/readline.h .
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  const int maxLength = 50;  // maximum length of a name (minus 2)
  char names[maxNames][maxLength];
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(fp); ) {
    if (readLine(names[n], maxLength)) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
names.c: In function ‘main’:
names.c:25:37: error: ‘fp’ undeclared (first use in this function)
   for (n = 0; n < maxNames && !feof(fp); ) {
                                     ^~
names.c:25:37: note: each undeclared identifier is reported only once for each function it appears in
[cs50@flume ~/demo]$ emacs names.c

[1]+  Stopped                 emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  const int maxLength = 50;  // maximum length of a name (minus 2)
  char names[maxNames][maxLength];
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    if (readLine(names[n], maxLength)) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
/tmp/cccMVbnF.o: In function `main':
/net/class/cs50/demo/names.c:26: undefined reference to `readLine'
collect2: error: ld returned 1 exit status
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readline.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  const int maxLength = 50;  // maximum length of a name (minus 2)
  char names[maxNames][maxLength];
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    if (readLine(names[n], maxLength)) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
gcc: error: readline.c: No such file or directory
[cs50@flume ~/demo]$ cp ~cs50/examples/readline.c .
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readline.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  const int maxLength = 50;  // maximum length of a name (minus 2)
  char names[maxNames][maxLength];
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    if (readLine(names[n], maxLength)) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
[cs50@flume ~/demo]$ ./names 
david
mary
joe
ellen
4 names
0: david
1: mary
2: joe
3: ellen
[cs50@flume ~/demo]$ fg
emacs names.c
[cs50@flume ~/demo]$ cp ~cs50/examples/readlinep.c .
cp: '/net/class/cs50/examples/readlinep.c' and './readlinep.c' are the same file
[cs50@flume ~/demo]$ cp ~cs50/examples/readlinep.h .
cp: '/net/class/cs50/examples/readlinep.h' and './readlinep.h' are the same file
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readline.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  char *names[maxNames];     // array of pointers to names
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    names[n] = readlinep();
    if (names[n] != NULL) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
names.c: In function ‘main’:
names.c:25:16: warning: implicit declaration of function ‘readlinep’ [-Wimplicit-function-declaration]
     names[n] = readlinep();
                ^~~~~~~~~
names.c:25:14: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
     names[n] = readlinep();
              ^
/tmp/ccayU8m7.o: In function `main':
/net/class/cs50/demo/names.c:25: undefined reference to `readlinep'
collect2: error: ld returned 1 exit status
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readline.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  char *names[maxNames];     // array of pointers to names
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    names[n] = readlinep();
    if (names[n] != NULL) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
names.c: In function ‘main’:
names.c:25:16: warning: implicit declaration of function ‘readlinep’ [-Wimplicit-function-declaration]
     names[n] = readlinep();
                ^~~~~~~~~
names.c:25:14: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
     names[n] = readlinep();
              ^
/tmp/cczE5wDq.o: In function `main':
/net/class/cs50/demo/names.c:25: undefined reference to `readlinep'
collect2: error: ld returned 1 exit status
[cs50@flume ~/demo]$ fg
-bash: fg: current: no such job
[cs50@flume ~/demo]$ emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readlinep.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  char *names[maxNames];     // array of pointers to names
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    names[n] = readlinep();
    if (names[n] != NULL) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s", i, names[i]);
  }
}
[cs50@flume ~/demo]$ ./names 
mary
joseph
fred
billie
4 names
0: mary1: joseph2: fred3: billie[cs50@flume ~/demo]$ fg
-bash: fg: current: no such job
[cs50@flume ~/demo]$ emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *   (read from a file named in argument)
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readlinep.h"

int main(const int argc, char *argv[])
{
  const int maxNames = 100;  // maximum number of names
  char *names[maxNames];     // array of pointers to names
  int n = 0;		      // number of names read

  // read the list of names
  for (n = 0; n < maxNames && !feof(stdin); ) {
    names[n] = readlinep();
    if (names[n] != NULL) {
      n++; // only increment if no error
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (int i = 0; i < n; i++) {
    printf("%d: %s\n", i, names[i]);
  }
}
[cs50@flume ~/demo]$ ./naes
-bash: ./naes: No such file or directory
[cs50@flume ~/demo]$ ./names
mary
joe
fred
mary
4 names
0: mary
1: joe
2: fred
3: mary
[cs50@flume ~/demo]$ emacs names.c

[1]+  Stopped                 emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include "readlinep.h"

struct listnode {
  char *name;
  struct listnode *next;
};

struct listnode *listnode_new(char *name);
bool list_insert(struct listnode *head, char *name);

int main(const int argc, char *argv[])
{
  struct listnode head = {NULL, NULL};
  int n = 0;		      // number of names read

  // read the list of names
  while ( !feof(stdin) ) {
    char *name = readlinep();
    if (name != NULL) {
      if (list_insert(&head, name)) {
	  n++; // only increment if no error
      }
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (struct listnode *node = head->next; node != NULL; node = node->next) {
    printf("%s\n", node->name);
  }
}

bool list_insert(struct listnode *head, char *name)
{
  struct listnode *node = listnode_new(name);

  if (head == NULL || node == NULL) {
    return false;
  } else {
    node->next = head->next;
    head->next = node;
  }
}

struct listnode *listnode_new(char *name)
{
  struct listnode *node = malloc(sizeof(struct listnode));
  if (node == NULL) {
    return NULL;
  } else {
    node->name = name;
    node->next = NULL;
    return node;
  }
}

names.c:22:1: error: unknown type name ‘bool’
 bool list_insert(struct listnode *head, char *name);
 ^~~~
names.c: In function ‘main’:
names.c:40:36: error: invalid type argument of ‘->’ (have ‘struct listnode’)
   for (struct listnode *node = head->next; node != NULL; node = node->next) {
                                    ^~
names.c: At top level:
names.c:45:1: error: unknown type name ‘bool’
 bool list_insert(struct listnode *head, char *name)
 ^~~~
names.c: In function ‘list_insert’:
names.c:50:12: error: ‘false’ undeclared (first use in this function)
     return false;
            ^~~~~
names.c:50:12: note: each undeclared identifier is reported only once for each function it appears in
names.c:55:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
[cs50@flume ~/demo]$ fg
emacs names.c

[1]+  Stopped                 emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "readlinep.h"

struct listnode {
  char *name;
  struct listnode *next;
};

struct listnode *listnode_new(char *name);
bool list_insert(struct listnode *head, char *name);

int main(const int argc, char *argv[])
{
  struct listnode head = {NULL, NULL};
  int n = 0;		      // number of names read

  // read the list of names
  while ( !feof(stdin) ) {
    char *name = readlinep();
    if (name != NULL) {
      if (list_insert(&head, name)) {
	  n++; // only increment if no error
      }
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (struct listnode *node = head->next; node != NULL; node = node->next) {
    printf("%s\n", node->name);
  }
}

bool list_insert(struct listnode *head, char *name)
{
  struct listnode *node = listnode_new(name);

  if (head == NULL || node == NULL) {
    return false;
  } else {
    node->next = head->next;
    head->next = node;
  }
}

struct listnode *listnode_new(char *name)
{
  struct listnode *node = malloc(sizeof(struct listnode));
  if (node == NULL) {
    return NULL;
  } else {
    node->name = name;
    node->next = NULL;
    return node;
  }
}

names.c: In function ‘main’:
names.c:41:36: error: invalid type argument of ‘->’ (have ‘struct listnode’)
   for (struct listnode *node = head->next; node != NULL; node = node->next) {
                                    ^~
names.c: In function ‘list_insert’:
names.c:56:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
[cs50@flume ~/demo]$ fg
emacs names.c

[1]+  Stopped                 emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "readlinep.h"

struct listnode {
  char *name;
  struct listnode *next;
};

struct listnode *listnode_new(char *name);
bool list_insert(struct listnode *head, char *name);

int main(const int argc, char *argv[])
{
  struct listnode head = {NULL, NULL};
  int n = 0;		      // number of names read

  // read the list of names
  while ( !feof(stdin) ) {
    char *name = readlinep();
    if (name != NULL) {
      if (list_insert(&head, name)) {
	  n++; // only increment if no error
      }
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (struct listnode *node = head.next; node != NULL; node = node->next) {
    printf("%s\n", node->name);
  }
}

bool list_insert(struct listnode *head, char *name)
{
  struct listnode *node = listnode_new(name);

  if (head == NULL || node == NULL) {
    return false;
  } else {
    node->next = head->next;
    head->next = node;
  }
}

struct listnode *listnode_new(char *name)
{
  struct listnode *node = malloc(sizeof(struct listnode));
  if (node == NULL) {
    return NULL;
  } else {
    node->name = name;
    node->next = NULL;
    return node;
  }
}

names.c: In function ‘list_insert’:
names.c:56:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
[cs50@flume ~/demo]$ fg
emacs names.c
[cs50@flume ~/demo]$ cat names.c ; mygcc names.c readlinep.c -o names
/* 
 * names2.c - read in a list of names from stdin
 *
 * usage: names <filename
 * filename: includes list of names, one per line
 * stdin: used if filename not specified
 * stdout: numbered list of names, one per line
 * 
 * David Kotz, April 2016, 2017
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "readlinep.h"

struct listnode {
  char *name;
  struct listnode *next;
};

struct listnode *listnode_new(char *name);
bool list_insert(struct listnode *head, char *name);

int main(const int argc, char *argv[])
{
  struct listnode head = {NULL, NULL};
  int n = 0;		      // number of names read

  // read the list of names
  while ( !feof(stdin) ) {
    char *name = readlinep();
    if (name != NULL) {
      if (list_insert(&head, name)) {
	  n++; // only increment if no error
      }
    }
  }
  printf("%d names\n", n);
  // print the list of names; note each name ends in newline.
  for (struct listnode *node = head.next; node != NULL; node = node->next) {
    printf("%s\n", node->name);
  }
}

bool list_insert(struct listnode *head, char *name)
{
  struct listnode *node = listnode_new(name);

  if (head == NULL || node == NULL) {
    return false;
  } else {
    node->next = head->next;
    head->next = node;
    return true;
  }
}

struct listnode *listnode_new(char *name)
{
  struct listnode *node = malloc(sizeof(struct listnode));
  if (node == NULL) {
    return NULL;
  } else {
    node->name = name;
    node->next = NULL;
    return node;
  }
}

[cs50@flume ~/demo]$ ./names
mary
jospeh
dave
mom
dad
billy
sally
rama
8 names
rama
sally
billy
dad
mom
dave
jospeh
mary
[cs50@flume ~/demo]$ emacs names5.
[cs50@flume ~/demo]$ emacs names5.c
[cs50@flume ~/demo]$