I have populated a structure with data and wrote it into a binary file. The problem is, when I try to read it back, it doesn't show the structure correctly! Here's the code...
#define MAXS 30
typedef struct {
char id[50];
int pct1, pct2;
} TStudd;
int ReadStruct(FILE* f, TStudd as ){
int i=0;
while (i < MAXS && fscanf(f, "%s" , as.id) == 1)
{
fscanf (f, "%i %i", &as.pct1, &as.pct2);
i++;
}
return i;//total number of read people
}
int WriteBinary(FILE* f, TStudd as){
int pct1, pct2, i;
pct1 = as.pct1;
pct2 = as.pct2;
i = fwrite(as.id, sizeof(as.id), 1,f);
if( i != 1) return -1;
i = fwrite(&pct1, sizeof(pct1), 1,f);
if( i != 1) return -2;
i = fwrite(&pct2, sizeof(pct2), 1,f);
if( i != 1) return -3;
return 0;
}
int ReadBinary(FILE* f){
char id [50];
int pct1, pct2, i;
i = fread(id, sizeof(id), 1,f);
if( i != 1) return -1;
printf("%s", id);
i = fread(&pct1, sizeof(pct1), 1,f);
if( i != 1) return -2;
printf("%i", pct1);
i = fread(&pct2, sizeof(pct2), 1,f);
if( i != 1) return -3;
printf("%i", pct2);
return 0;
}
g = fopen(sursa, "rt");
v = ReadStruct(g, ps);
printf("%i\n", v);
f = fopen(dest, "w+b");
}
if ( ReadBinary(f, ps) < 0){
printf("Eroare scriere\n");
return 1;
}
if ( WriteBinary(f) < 0 ){
printf("Eroare citire\n");
return 1;
};
fclose(g);
fclose(f);
What should I change? Thank you!
Platform is Windows 7 64 bit and the file isn't subject to any conversion (just writing and reading stuff from it)
Related
I am trying to take a list of MAC Addresses and Device names from a text file and store them in an array called list;
struct list {
char ch;
char a[2], b[2], c[2], d[2], e[2], f[2], g[2], alias[32]; //chars a-g are supposed to be a maximum of two characters long to store the different segments of the mac addresses, and the alias stores the device name up to 32 characters.
};
The main function here, as of right now is supposed to open the file "Inet.txt" and read each character individually using "char cur = fgetc." The function then assigns the different parts of the MAC address to its corresponding position in chars a-g of the list struct, and the alias char if the function goes more than 2 chars without reaching a ":" or a " ". The length of the current char is represented by the variable k, which increases every time the program detects a letter or a number, and is reset to -1 every time variable 'cur' is assigned to something. There is also an array "struct list *head[32]; " which stores each line separately, the line number being identified by the variable "int i", which increases by one every time "cur == '\n'" starting at "int = 0." The main function is as follows;
int main()
{
FILE *fp;
char cur, temp[32], temp2[32], p;
struct list *head[32];
head[0]=(struct list*)malloc(sizeof(struct list));
int num = 0, d, data, devices, i = 0, j = -1, k = -1, l = 0;
char arr[100][2];
int count = 0;
//head = current = NULL;
fp = fopen("Inet.txt", "r");
if(fp==NULL)
{
printf("Error opening file.");
}
while((cur = fgetc(fp)) != EOF)
{
//stringchecker(cur)!=0
if((cur >= 48 && cur <= 57)||(cur >= 97 && cur <= 122)||(cur >= 65 && cur <= 90))
{
k++; //counter for temp array size
if(cur >= 97 && cur <= 122)
{
temp[k] = cur-32;
}
else
{
temp[k] = cur;
}
if(k>1)
{
strncpy(temp2, temp, k+1);
temp2[k+1] = '\0';
aloc(&head[i],temp2,7);
// k = -1;
}
}
else if(cur == ':')
{
if(count == 0)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 1)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 2)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 3)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 4)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 5)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
count++;
k = -1;
}
else if(cur == ' ')
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,6);
k = -1;
}
else if(cur == '\n')
{
printf("\n%s:%s:%s:%s:%s%s\nALIAS: %s", (*head[i]).a,(*head[i]).b,(*head[i]).c,(*head[i]).d,(*head[i]).e,(*head[i]).f,(*head[i]).alias);
exit(0);
devices++;
data++;
count = 0;
num = -1;
i++;
j = -1;
k = -1;
head[i]=(struct list*)malloc(sizeof(struct list));
//exit(0);
}
}
fclose(fp);
return 0;
}
The "aloc()" function assigns the current char up to 16 characters to a-g or alias depending on the value of the variable count, which is a parameter of this function. The aloc() function is as follows;
void aloc(struct list **head, char ch[16], int count) //assigns ch value to specific variable of the current head based on the value of count 1-7
{
if(count == 0)
{
strncpy((*head)->a,ch, 2);
}
else if(count == 1)
{
strncpy((*head)->b,ch, 2);
}
else if(count == 2)
{
strncpy((*head)->c,ch, 2);
}
else if(count == 3)
{
strncpy((*head)->d,ch, 2);
}
else if(count == 4)
{
strncpy((*head)->e,ch, 2);
}
else if(count == 5)
{
strncpy((*head)->f,ch, 2);
}
else if(count == 6)
{
strncpy((*head)->g,ch, 2);
}
else if(count == 7)
{
strncpy((*head)->alias,ch, 16);
}
}
The input text file "Inet.txt" is as follows;
A0:FB:C5:44:b8:45 PLATTE
58:24:29:0f:c8:ee JET
F1:C0:11:16:53:1F Wabash
A0:FB:C5:32:15:10 GREEN
33:68:29:a1:b2:3c Charlie
58:24:29:0A:0B:C0 BAKER
GG:01:X0:99:1A:45 FOXTROT
The main problem I am having with this code is the variables a-g are not being assigned correctly. When I run the program to only read the first line, I get the following output:
A0FBC544B8:FBC544B8:C544B8:44B8:B8
ALIAS: PLATTE%
When the output should be:
A0:FB:C5:44:B8
ALIAS: PLATTE
I am not sure which line is causing the entire mac address to be assigned to char a of the current list. I will post the code as I have it in its entirety here to avoid confusion.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
struct list {
char ch;
char a[2], b[2], c[2], d[2], e[2], f[2], g[2], alias[32];
};
void aloc(struct list **head, char ch[16], int count)
{
if(count == 0)
{
strncpy((*head)->a,ch, 2);
}
else if(count == 1)
{
strncpy((*head)->b,ch, 2);
}
else if(count == 2)
{
strncpy((*head)->c,ch, 2);
}
else if(count == 3)
{
strncpy((*head)->d,ch, 2);
}
else if(count == 4)
{
strncpy((*head)->e,ch, 2);
}
else if(count == 5)
{
strncpy((*head)->f,ch, 2);
}
else if(count == 6)
{
strncpy((*head)->g,ch, 2);
}
else if(count == 7)
{
strncpy((*head)->alias,ch, 16);
}
}
int main()
{
FILE *fp;
char cur, temp[32], temp2[32], p;
struct list *head[32];
head[0]=(struct list*)malloc(sizeof(struct list));
int num = 0, d, data, devices, i = 0, j = -1, k = -1, l = 0;
char arr[100][2];
int count = 0;
//head = current = NULL;
fp = fopen("Inet.txt", "r");
if(fp==NULL)
{
printf("Error opening file.");
}
while((cur = fgetc(fp)) != EOF)
{
//stringchecker(cur)!=0
if((cur >= 48 && cur <= 57)||(cur >= 97 && cur <= 122)||(cur >= 65 && cur <= 90))
{
k++; //counter for temp array size
if(cur >= 97 && cur <= 122)
{
temp[k] = cur-32;
}
else
{
temp[k] = cur;
}
if(k>1)
{
strncpy(temp2, temp, k+1);
temp2[k+1] = '\0';
aloc(&head[i],temp2,7);
// k = -1;
}
}
else if(cur == ':')
{
if(count == 0)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 1)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 2)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 3)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 4)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
else if(count == 5)
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,count);
}
count++;
k = -1;
}
else if(cur == ' ')
{
strncpy(temp2, temp, 2);
temp2[2] = '\0';
aloc(&head[i],temp2,6);
k = -1;
}
else if(cur == '\n')
{
printf("\n%s:%s:%s:%s:%s%s\nALIAS: %s", (*head[i]).a,(*head[i]).b,(*head[i]).c,(*head[i]).d,(*head[i]).e,(*head[i]).f,(*head[i]).alias);
exit(0);
devices++;
data++;
count = 0;
num = -1;
i++;
j = -1;
k = -1;
head[i]=(struct list*)malloc(sizeof(struct list));
//exit(0);
}
}
fclose(fp);
return 0;
}
I initially tried writing this program using linked lists, but I thought it would be easier to keep track of an array of list structs for use later in my program. However I keep getting the same problem with my output. Any help is appreciated.
If you remove exit(0); from the block here
else if(cur == '\n')
{
printf(/* ... */);
exit(0);
devices++;
data++;
count = 0;
/* ... */
then this program appears to work1.
I say "appears" because this program invokes Undefined Behaviour by printing non null-terminated buffers with the printf specifier %s.
You need to either specify a precision, being the maximum number of bytes to print, with each %s specifier. For example:
#include <stdio.h>
int main(void)
{
char buf[2] = "AB"; /* the null byte is not stored */
printf("%2s\n", buf);
}
Or, you need to ensure your buffers are large enough to store a desired string length plus the null-terminating byte. If you want to store a string of length 2, your buffer must be at least of size 3.
#include <stdio.h>
int main(void)
{
char buf[3] = "AB"; /* the null byte IS stored */
printf("%s\n", buf);
}
Note that strncpy is notoriously hard to use, as it does not null-terminate the buffer if the length of the source string is greater than or equal to the size provided.
1. You must also change char cur to int cur. On platforms when char is an unsigned type, you will not be able to reliably test against the negative int value of EOF. fgetc returns an int for this reason.
As pointed out in the comments, avoid magic numbers and instead use the functions found in <ctype.h>.
If your file contents are predictably formatted, you can just use fgets + sscanf to read each line. For example:
#include <stdio.h>
#include <stdlib.h>
#define MAX_ADDRS 256
struct address {
char a[3];
char b[3];
char c[3];
char d[3];
char e[3];
char f[3];
char alias[32];
};
size_t read_macs(struct address *addrs, size_t limit, FILE *f)
{
char buffer[512];
size_t n = 0;
while (n < limit && fgets(buffer, sizeof buffer, f)) {
int cv = sscanf(buffer, "%2s:%2s:%2s:%2s:%2s:%2s%31s",
addrs[n].a, addrs[n].b, addrs[n].c,
addrs[n].d, addrs[n].e, addrs[n].f,
addrs[n].alias);
if (7 == cv)
n++;
}
return n;
}
int main(int argc, char **argv)
{
if (argc < 2) {
fprintf(stderr, "usage: %s FILENAME\n", *argv);
return EXIT_FAILURE;
}
FILE *file = fopen(argv[1], "r");
if (!file) {
perror(argv[1]);
return EXIT_FAILURE;
}
struct address store[MAX_ADDRS];
size_t length = read_macs(store, MAX_ADDRS, file);
fclose(file);
for (size_t i = 0; i < length; i++)
printf("%s (%s:....:%s)\n",
store[i].alias, store[i].a, store[i].f);
}
$ ./a.out Inet.txt
PLATTE (A0:....:45)
JET (58:....:ee)
Wabash (F1:....:1F)
GREEN (A0:....:10)
Charlie (33:....:3c)
BAKER (58:....:C0)
FOXTROT (GG:....:45)
I need some help just starting off my code for this program. This is my first time reading a file in c and I have been stuck starting it off. Essentially, I need to read in two files to calculate Manhattan Distance and output the ID for each file and the closest distance. The files look something like this:
3,2
0, 3.4, 4.3
1, 4.5, 6.1
2, 7.2, 3.9
3,2
0, 5.9, 6.7
1, 8.5, 1.2
2, 9.8, 4.9
My current code only outputs the table and I am trying to find a way to use columns as a way to calculate Manhattan distance. The 3,2 signifies the rows and columns and the 0,1,2 are the IDs. Here is the current code I have found online and modified a bit that I thought may be useful.
#include <stdio.h>
#include <string.h>
int main()
{
FILE* testFile = fopen("Test.txt", "r");
if (!testFile)
printf("Can't open file\n");
else {
char buffer[1024];
int row = 0;
int column = 0;
while (fgets(buffer, 1024, testFile)) {
column = 0;
row++;
if (row == 1)
continue;
// Splitting the data
char* value = strtok(buffer, ", ");
while (value) {
// Column 1
if (column == 0) {
printf("TestID:");
}
// Column 2
if (column == 1) {
printf("\tx1: ");
}
// Column 3
if (column == 2) {
printf("\ty1: ");
}
printf("%s", value);
value = strtok(NULL, ", ");
column++;
}
printf("\n");
}
// Close the file
fclose(testFile);
}
return 0;
}
Here's a basic example demonstrating one method of parsing your input files with strtod and strtoul:
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct mat {
int rows;
int columns;
double *data;
};
void
show(const struct mat *A)
{
double *d = A->data;
for( int i = 0; i < A->rows; i += 1 ){
for( int j = 0; j < A->columns; j += 1 ){
printf("%f\t", *d++);
}
putchar('\n');
}
}
/*
* Return nonzero if the first non-whitespace
* character after *e is not v. Terminate search
* at a newline.
*/
int
expect_next(char **e, const char v)
{
char *end = *e;
while( isspace(*end) && *end != '\n' ){
end += 1;
}
*e = end + 1;
return *end != v;
}
int
get_data(struct mat *A, const char *path)
{
unsigned line = 1;
FILE* testFile = fopen(path, "r");
if( testFile == NULL ){
perror(path);
return 0;
}
char buffer[1024];
char *end = buffer;
if( fgets(buffer, sizeof buffer, testFile) == NULL ){
if( ferror(testFile) ){
perror(path);
} else {
goto bad_input;
}
return 0;
}
A->rows = strtoul(buffer, &end, 10);
if( expect_next(&end, ',') ){
goto bad_input;
}
A->columns = strtoul(end, &end, 10);
if( expect_next(&end, '\n') ){
goto bad_input;
}
A->data = malloc(A->rows * A->columns * sizeof *A->data);
if( A->data == NULL ){
perror("malloc");
return 0;
}
double *val = A->data;
unsigned row = 0;
while( NULL != fgets(buffer, sizeof buffer, testFile) ){
line += 1;
unsigned v = strtoul(buffer, &end, 10);
if( v != row ){
goto bad_input;
}
if( expect_next(&end, ',') ){
goto bad_input;
}
unsigned col = 0;
while( col < A->columns && *end ){
*val++ = strtod(end, &end);
if( expect_next(&end, ++col == A->columns ? '\n' : ',') ){
goto bad_input;
}
}
if( col != A->columns ){
goto bad_input;
}
row += 1;
}
if( row != A->rows ){
goto bad_input;
}
if( fclose(testFile) ){
perror(path);
}
return 1;
bad_input:
fprintf(stderr, "%s: Invalid input at line %u, column %u\n", path,
line, (unsigned)(end - buffer));
return 0;
}
int
main(int argc, char ** argv)
{
char *args[] = { NULL, "/dev/stdin", NULL };
if( argc < 2 ){
argv = args;
}
for( argv += 1; *argv; argv += 1 ){
struct mat A;
if( get_data(&A, *argv) ){
show(&A);
}
}
}
I'm recently new to programming but this assignment has proven to be my most difficult. The program is suppose to read in a .txt file with the following format
input_base number output_base
and outputs the results. the bases can only range from 2-36 For example:
input: 2 10 4
output: 2
My program reads in each part of the line and stores them respectively. I then go through the steps to convert the number into the output base and then print it backwards. My problem is that the program runs fine and prints all the stored values and calculated values, but once I add in my "base_conversion" function the program no longer works and my friend even said it gave him a segmentation fault. I don't really know what could be causing it. Any help would be appreciated. Thank you.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
void read_file_to_buffer(FILE *file);
char *buffer = NULL;
void string_check(char *buffer);
int char_to_int(char c);
int int_conversion(int x, int y);
void base_conversion(int end_number, int out_base);
int main(int argc, char *argv[]){
FILE *file = NULL;
if ( argc != 2 ){
fprintf(stderr, "Error: To many/few arguments\n");
exit(EXIT_FAILURE);
}
else {
file = fopen(argv[1], "rb");
if (file == NULL) {
fprintf(stderr, "Error: could not open file '%s'\n", argv[1]);
exit(EXIT_FAILURE);
}
else{
printf("File %s opened!\n", argv[1]);
}
}
read_file_to_buffer(file);
string_check(buffer);
fclose(file);
free(buffer);
buffer = NULL;
exit(EXIT_SUCCESS);
}
void read_file_to_buffer(FILE *file) {
long file_size = 0;
if(buffer != NULL){
fprintf(stderr, "buffer in use\n");
exit(EXIT_FAILURE);
}
rewind(file);
if (fseek(file, 0, SEEK_END) != 0){
perror("Could not seek to end of file");
exit(EXIT_FAILURE);
}
file_size = ftell(file);
if (file_size < 0){
perror("could not tell size of file");
exit(EXIT_FAILURE);
}
rewind(file);
buffer = (char *)malloc(sizeof(char) * (file_size + 1));
if (buffer == NULL){
fprintf(stderr, "Could not allocate memory");
exit(EXIT_FAILURE);
}
if(fread(buffer, sizeof(char), (size_t)file_size, file) != file_size){
fprintf(stderr, "Could not read file\n");
exit(EXIT_FAILURE);
}
buffer[file_size] = '\0';
return;
}
void string_check(char *buffer){
int i = 0;
int j = 0;
char base_in[2];
char number[50];
char base_out[2];
int actual_number[100];
int end_number = 0;
int x = 0;
int y = 0;
int in_base;
int out_base;
while( buffer[i] != '\0'){
if (buffer[i] != '#' && buffer[i] != ' ' && buffer[i] != '\n' && buffer[i] != '\r'){
while (buffer[i] != ' '){
base_in[j] = buffer[i];
i++;
j++;
}
j = 0;
i++;
if (base_in[1] != '\0'){
x = char_to_int(base_in[0]);
y = char_to_int(base_in[1]);
in_base = int_conversion(x, y);
x = 0;
y = 0;
}
else{
in_base = char_to_int(base_in[0]);
}
while (buffer[i] != ' '){
number[j] = buffer[i];
i++;
j++;
}
int q;
q=j;
j=0;
while (number[j] != '\0'){
actual_number[j] = char_to_int(number[j]);
end_number = end_number + pow(in_base, q-1) * actual_number[j];
j++;
q--;
}
j = 0;
i++;
while (buffer[i] != '\n' && buffer[i] != '\0'){
base_out[j] = buffer[i];
i++;
j++;
}
if (base_out[1] != '\0'){
x = char_to_int(base_out[0]);
y = char_to_int(base_out[1]);
out_base = int_conversion(x, y);
x = 0;
y = 0;
}
else{
out_base = char_to_int(base_out[0]);
}
j = 0;
i++;
base_conversion(end_number, out_base);
}
else{
while (buffer[i] != '\n' && buffer[i] != '\0'){
i++;
}
}
i++;
}
return;
}
int char_to_int(char c){
char map[] = "0123456789abcdefghijklmnopqrstuvwxyz";
int result = -1;
char *next = map;
while(*next != '\0'){
if(*next == c){
result = next - map;
break;
}
next++;
}
return result;
}
int int_conversion(int x, int y){
int value;
value = (x * 10) + y;
return value;
}
void base_conversion(int end_number, int out_base){
int remainder[100];
char map[] = "0123456789abcdefghijklmnopqrstuvwxyz";
int index = 0;
int i;
while (end_number != 0){
remainder[index] = end_number % out_base;
end_number = end_number / out_base;
index++;
}
for (i=0; i<index; i++){
printf("%c", map[remainder[index-1]]);
}
printf("\n");
return;
}
OP's base_conversion() is messed.
Loop prints same character repeatedly.
for (i=0; i<index; i++){
printf("%c", map[remainder[index-1]]); // Why same character?
}
Code is using signed math and % and can create negative remainders which may be used as array index.
remainder[index] = end_number % out_base; // result may be negative.
...
printf("%c", map[remainder[index-1]]); // accessing out of bounds with negative
Suggested simplification.
void base_conversion_helper(unsigned end_number, int out_base){
if (end_number >= out_base) base_conversion_helper(end_number/out_base, out_base);
putchar("0123456789abcdefghijklmnopqrstuvwxyz"[end_number % outbase]);
}
void base_conversion(unsigned end_number, int out_base){
assert(out_base >= 2 && out_base <= 36);
base_conversion_helper(end_number, out_base);
putchar('\n');
}
So this program crashes and tells me "Aborted (core dumped)" but only when my decleration of "GENERATIONS" is greater than 6... I know its a pain that I've uploaded the whole code but I really cant figure out where it is other than it's after the return from "fibonacci_quasicrystal_generator(GENERATIONS, crystal);", as the printf statement just after gets printed, then the message appears. Code below:
#define GENERATIONS 5
#define OUTFILE "frequencies.txt"
#define GNUPLOT_EXE "gnuplot"
#define GNUPLOT_SCRIPT "frequencyplot.script"
static void fibonacci_quasicrystal_generator(int generations, char * chain);
static int plot();
int main()
{
double k = 1.0, m_a = 100.0, m_b = 1.0, m = 0.0;
char * crystal = malloc(2);
//strcopy(crystal, "A"); //gsl_vector * y_vector = gsl_vector_calloc(CHAIN_LENGTH);
fibonacci_quasicrystal_generator(GENERATIONS, crystal);
if (crystal == NULL){
printf("Crystal write failed.");
exit(0);
}
int chain_length = strlen(crystal);
printf("%i member Crystal generated, after %i generations.\n", chain_length, GENERATIONS);
gsl_matrix * a_matrix = gsl_matrix_calloc(chain_length, chain_length);
gsl_matrix * b_matrix = gsl_matrix_calloc(chain_length, chain_length);
gsl_matrix_set_identity(b_matrix);
gsl_vector * eigenvalues_vector = gsl_vector_calloc(chain_length);
for (int i = 0; i < chain_length; ++i){
if (crystal[i] == 'A'){
m = m_a;
} else {
m = m_b;
}
for (int j = 0; j < chain_length; ++j){
if ((i == j) && (i != 0 && i != chain_length)){
gsl_matrix_set(a_matrix, i, j,(2*k)/m);
}
else if (i == j-1){
gsl_matrix_set(a_matrix, i, j,(-1)*(k/m));
}
else if (i == j+1){
gsl_matrix_set(a_matrix, i ,j, (-1)*(k/m));
}
}
}
gsl_eigen_gensymm_workspace * workspace = gsl_eigen_gensymm_alloc(chain_length);
gsl_eigen_gensymm(a_matrix, b_matrix, eigenvalues_vector, workspace);
gsl_eigen_gensymm_free(workspace);
free(crystal);
gsl_matrix_free(a_matrix);
gsl_matrix_free(b_matrix);
gsl_sort_vector(eigenvalues_vector);
FILE * outfile = fopen(OUTFILE, "w");
for (int i = 0; i < chain_length; ++i){
fprintf(outfile, "%e \t%i \r\n", pow(gsl_vector_get(eigenvalues_vector, i),2), i);
}
fclose(outfile);
gsl_vector_free(eigenvalues_vector);
plot();
return 0;
}
static void fibonacci_quasicrystal_generator(int generations, char * chain){
printf("generating fibonacci quasicrystal...\n");
int i;
i = 0;
char * chain_1 = malloc(2), * chain_2 = malloc(2), * tmp = malloc(2);
strcpy(chain_1, "B");
strcpy(chain_2, "A");
size_t chain_1_size = strlen(chain_1) + 1, chain_2_size = strlen(chain_2) + 1;
if (generations == 1){
chain = realloc(chain, chain_1_size);
snprintf(chain, chain_1_size, "%s", chain_1);
}
else if (generations == 2){
chain = realloc(chain, chain_2_size);
snprintf(chain, chain_2_size, "%s", chain_2);
}
else if (generations > 2){
size_t chain_3_size = strlen(chain_1) + strlen(chain_2) + 1;
char * chain_3 = malloc(chain_3_size);
printf("%i\n", generations);
for (i = 0; i < generations - 1; ++i){
printf("%i\n", i);
snprintf(chain_3, chain_3_size, "%s%s", chain_1, chain_2);
chain_1_size = chain_2_size;
chain_2_size = chain_3_size;
if ((tmp = realloc(chain_1, chain_1_size)) != NULL){
chain_1 = tmp;
}
if ((tmp = realloc(chain_2, chain_2_size)) != NULL){
chain_2 = tmp;
}
snprintf(chain_1, chain_1_size, "%s", chain_2);
snprintf(chain_2, chain_2_size, "%s", chain_3);
if (i < generations - 2){
chain_3_size = strlen(chain_1) + strlen(chain_2) + 1;
if ((tmp = realloc(chain_3, chain_3_size)) != NULL){
chain_3 = tmp;
} else {
printf("oops!\n");
exit(1);
}
}
}
chain = realloc(chain, chain_3_size);
snprintf(chain, chain_3_size, "%s", chain_3);
free(chain_3);
}
free(chain_1);
free(chain_2);
}
static int plot(){
char command[PATH_MAX];
snprintf(command, sizeof(command), "%s %s", GNUPLOT_EXE, GNUPLOT_SCRIPT);
system(command);
return 0;
}
The problem is that char *chain into fibonacci_quasicrystal_generator function has local scope: the function does not modify the crystal pointer of main, so that pointer is left with 2 bytes.
You can change the function to
static char *fibonacci_quasicrystal_generator(int generations, char * chain)
{
// YOUR STUFF
return chain;
}
And call it from main using
crystal = fibonacci_quasicrystal_generator(GENERATIONS, crystal);
You can achieve the same using a double pointer so
static void ibonacci_quasicrystal_generator(int generations, char ** chain)
Any idea why this program will fail in downloading images from page #12 while it did pages 1-9 perfectly? I really don't know how can I debug. Maybe there's a problem with wget when it doesn't find the first image? http://img717.imageshack.us/img717/7954/white2u.png
#include <stdio.h>
#include <stdlib.h> // for using system calls
#include <unistd.h> // for sleep
int main ()
{
char body[] = "forum-post-body-content", notes[] = "p-comment-notes", img[] = "img src=", link[200], cmd[200]={0}, file[10];
int c, pos = 0, pos2 = 0, fin = 0, i, j, num = 0, found = 0;
FILE *fp;
for (i = 12; i <= 149; ++i)
{
sprintf(cmd,"wget -O page%d.txt 'http://www.mtgsalvation.com/forums/creativity/artwork/340782-official-digital-rendering-thread?page=%d'",i,i);
system(cmd);
sprintf(file, "page%d.txt", i);
fp = fopen (file, "r");
while ((c = fgetc(fp)) != EOF)
{
if (body[pos] == c)
{
if (pos == 22)
{
pos = 0;
while (fin == 0)
{
c = fgetc (fp);
if (feof (fp))
break;
if (notes[pos] == c)
{
if (pos == 14)
{
fin = 1;
pos = -1;
}
++pos;
}
else
{
if(pos > 0)
pos = 0;
}
if (img[pos2] == c)
{
if (pos2 == 7)
{
pos2 = 0;
while (found == 0)
{
c = fgetc (fp); // get char from file
link[pos2] = c;
if (pos2 > 0)
{
if(link[pos2-1] == 'g' && link[pos2] == '\"')
{
found = 1;
}
}
++pos2;
}
--pos2;
found = 0;
char link2[pos2];
for (j = 1; j < pos2; ++j)
{
link2[j - 1] = link[j];
}
link2[j - 1] = '\0';
sprintf(cmd, "wget -O /home/arturo/Dropbox/Digital_Renders/%d \'%s\'", ++num, link2);
system(cmd);
pos2 = -1;
}
++pos2;
}
else
{
if(pos2 > 0)
pos2 = 0;
}
}
fin = 0;
}
++pos;
}
else
pos = 0;
}
// closing file
fclose (fp);
if (remove (file))
fprintf(stderr, "Can't remove file\n");
}
}
char file[10];
"page12.txt" has 11 characters in it including the null character. Please just do something like char file[128]. Memory is cheap. Time spent debugging is expensive.
You have an overflow.
file[10];
page1.txt = 10 characters including the null terminator
page12.txt = 11 characters
Look into to the safe functions like snprintf()