Re: adding colums to text
- From: pete <pfiland@xxxxxxxxxxxxxx>
- Date: Sat, 28 Jun 2008 23:11:13 -0400
Bill Cunningham wrote:
I have a row of values like such, placed in a text file by fprintf.
10.50
10.25
10.00
10.75
11.00
What I want to do to the above colum is add a new column right beside it which is a total of these values and then average them in another column. For example.
11.00 52.50
In another column is the average of the 5.
11.00 52.50 10.50
I am assuming that fprintf is going to have to be used and maybe freopen.
Text files and linked lists, go together like hot dogs and mustard.
/* BEGIN new.c output */
File is open for writing.
File lines:
10.50
10.25
10.00
10.75
11.00
File is closed.
File is open for reading.
Reading file into a linked list...
File is closed.
File is open for writing.
List is freed.
File is closed.
File is open for reading.
File lines:
10.50 52.50 10.50
10.25 52.50 10.50
10.00 52.50 10.50
10.75 52.50 10.50
11.00 52.50 10.50
Line reading buffer is freed.
File is closed.
File is removed.
/* END new.c output */
/* BEGIN new.c */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#define DOUBLES {10.5, 10.25, 10, 10.75, 11}
#define NMEMB(A) (sizeof (A) / sizeof *(A))
typedef struct list_node {
struct list_node *next;
void *data;
} list_type;
int get_line(char **lineptr, size_t *n, FILE *stream);
list_type *list_append
(list_type **head, list_type *tail, void *data, size_t size);
void list_free(list_type *node, void (*free_data)(void *));
int main(void)
{
int rc;
size_t index;
FILE *fp;
long unsigned count = 0;
double sum = 0.0;
char fn[L_tmpnam];
double array[] = DOUBLES;
char *buff = NULL;
size_t size = 0;
list_type *head = NULL;
list_type *tail = NULL;
puts("/* BEGIN new.c output */\n");
tmpnam(fn);
fp = fopen(fn, "w");
if (fp == NULL) {
fputs("fopen(fn), \"w\") == NULL\n", stderr);
exit(EXIT_FAILURE);
}
puts("File is open for writing.");
puts("File lines:");
for (index = 0; index != NMEMB(array); ++index) {
fprintf( fp, "%.2f\n", array[index]);
fprintf(stdout, "%.2f\n", array[index]);
}
fclose(fp);
puts("File is closed.\n");
fp = fopen(fn, "r");
if (fp == NULL) {
fputs("fopen(fn, \"r\") == NULL\n", stderr);
exit(EXIT_FAILURE);
}
puts("File is open for reading.");
puts("Reading file into a linked list...");
while ((rc = get_line(&buff, &size, fp)) > 0) {
tail = list_append(&head, tail, buff, rc);
if (tail == NULL) {
fputs("tail == NULL\n", stderr);
break;
}
++count;
}
fclose(fp);
puts("File is closed.");
fp = fopen(fn, "w");
if (fp == NULL) {
fputs("fopen(fn), \"w\") == NULL\n", stderr);
exit(EXIT_FAILURE);
}
puts("\nFile is open for writing.");
for (tail = head; tail != NULL; tail = tail -> next) {
sum += atof(tail -> data);
}
for (tail = head, index = 0; index != count; ++index) {
fprintf(fp, "%.2f %.2f %.2f\n",
array[index], sum, sum / count);
tail = tail -> next;
if (tail == NULL) {
break;
}
}
list_free(head, free);
puts("List is freed.");
fclose(fp);
puts("File is closed.");
fp = fopen(fn, "r");
if (fp == NULL) {
fputs("fopen(fn, \"r\") == NULL\n", stderr);
exit(EXIT_FAILURE);
}
puts("\nFile is open for reading.");
puts("File lines:");
while ((rc = get_line(&buff, &size, fp)) > 0) {
fprintf(stdout, "%s\n", buff);
}
free(buff);
buff = NULL;
size = 0;
puts("Line reading buffer is freed.");
fclose(fp);
puts("File is closed.");
remove(fn);
puts("File is removed.");
puts("\n/* END new.c output */");
return 0;
}
int get_line(char **lineptr, size_t *n, FILE *stream)
{
int rc;
void *p;
size_t count;
count = 0;
while ((rc = getc(stream)) != EOF
|| !feof(stream) && !ferror(stream))
{
++count;
if (count == (size_t)-2) {
if (rc != '\n') {
(*lineptr)[count] = '\0';
(*lineptr)[count - 1] = (char)rc;
} else {
(*lineptr)[count - 1] = '\0';
}
break;
}
if (count + 2 > *n) {
p = realloc(*lineptr, count + 2);
if (p == NULL) {
if (*n > count) {
if (rc != '\n') {
(*lineptr)[count] = '\0';
(*lineptr)[count - 1] = (char)rc;
} else {
(*lineptr)[count - 1] = '\0';
}
} else {
if (*n != 0) {
**lineptr = '\0';
}
ungetc(rc, stream);
}
count = 0;
break;
}
*lineptr = p;
*n = count + 2;
}
if (rc != '\n') {
(*lineptr)[count - 1] = (char)rc;
} else {
(*lineptr)[count - 1] = '\0';
break;
}
}
if (rc != EOF || !feof(stream) && !ferror(stream)) {
rc = INT_MAX > count ? count : INT_MAX;
} else {
if (*n > count) {
(*lineptr)[count] = '\0';
}
}
return rc;
}
list_type *list_append
(list_type **head, list_type *tail, void *data, size_t size)
{
list_type *node;
node = malloc(sizeof *node);
if (node != NULL) {
node -> next = NULL;
node -> data = malloc(size);
if (node -> data != NULL) {
memcpy(node -> data, data, size);
if (*head != NULL) {
tail -> next = node;
} else {
*head = node;
}
} else {
free(node);
node = NULL;
}
}
return node;
}
void list_free(list_type *node, void (*free_data)(void *))
{
list_type *next_node;
while (node != NULL) {
next_node = node -> next;
free_data(node -> data);
free(node);
node = next_node;
}
}
/* END new.c */
--
pete
.
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