I am learning C language. Here is a simple program I did to create 1000 text files.
#include <stdio.h>
#include <string.h>
char * create_filename(char *, char *, int);
int main(void)
{
char prefix_name[50] = "file_no_";
char snum[5];
int no_of_files = 1000;
FILE * fp = NULL;
for (int i = 0; i < no_of_files; i++)
{
fp = fopen( create_filename(prefix_name, snum, i + 1), "w");
fprintf(fp, "This is file no %d", i+1);
fclose(fp);
fp = NULL;
strcpy(prefix_name, "file_no_");
}
return 0;
}
char * create_filename(char * prefix_name, char * snum, int i)
{
sprintf(snum, "%d", i);
strcat(prefix_name, snum);
strcat(prefix_name, ".txt");
return prefix_name;
}
This runs as expected. But I want to know, how can I make this more efficient and as portable as possible. If I want to scale this up to, say 10000 text files, are there other approaches which will be better ?
Thanks
how can I make this more efficient and as portable as possible.
More error checking. Example: a failed fopen() can readily occur.
Realize that a huge amount of time will occur in fopen() and local code likely will have scant time improvements.
Avoid re-writing the prefix.
Use a helper function.
Example:
// Return count of successfully written files.
int create_many_files(const char *prefix, int count, const char *suffix) {
int n;
int len = snprintf(NULL, 0, "%s%n%d%s", prefix, &n, count, suffix);
if (len < 0) {
return 0;
}
// Use len to determine longest name and use a VLA or allocation.
// Consider using a fixed array when len is not too big.
char *filename = malloc((size_t)len + 1u);
if (filename == NULL) {
return 0;
}
strcpy(filename, prefix);
char *offset = filename + n;
for (int i = 0; i < count; i++) {
sprintf(offset, "%d%s", i + 1, suffix);
FILE *fp = fopen(filename, "w");
if (fp == NULL) {
free(filename);
return i;
}
fprintf(fp, "This is file no %d", i + 1);
fclose(fp);
}
free(filename);
return count;
}
Other potential error checks:
prefix == NULL
cout < 0
suffix == NULL
fprintf() < 0
fclose() != 0
Related
I have a .csv file. Let's say the data is like this:
Location 1,Location 2,Price,Rooms,Bathrooms,CarParks,Type,Area,Furnish
Upper-East-Side,New-York,310000,3,2,0,Built-up,1000,Partly
West-Village,New-York,278000,2,2,0,Built-up,1000,Partly
Theater-District,New-York,688000,3,2,0,Built-up,1000,Partly
Expected output (alphabetized):
Theater-District
Upper-East-Side
West-Village
How can I only show and alphabetize the first column (Location 1) of the file while also skipping the header?
This is currently my code but it's still in a "read and display" form.
#include <stdio.h>
int main()
{
FILE *fh;
fh = fopen("file.csv", "r");
if (fh != NULL)
{
int line_number = 0;
char c;
while ( (c = fgetc(fh)) != EOF )
{
if(line_number > 0 || c == '\n'){
putchar(c);
}
if(c == '\n'){
line_number++;
}
}
fclose(fh);
} else printf("Error opening file.\n");
return 0;
}
csv is not a well defined format so I suggest you use an existing csv library instead of parsing the data yourself. For instance, this will not work if the first field has any embedded commas. It relies on scanf() to allocate the line, and resizes the lines array as needed. This means there are no arbitrary limits.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int strcmp2(const void *a, const void *b) {
return strcmp((const char *) a, (const char *) b);
}
int main() {
FILE *f = fopen("unsorted.csv", "r");
if(!f) return 1;
char **lines = NULL;
size_t n = 0;
for(;; n++) {
char *location1;
int rv = fscanf(f, "%m[^,]%*[^\n]\n", &location1);
if(rv != 1) break;
char **tmp = realloc(lines, (n + 1) * sizeof *tmp);
if(!tmp) return 1;
lines = tmp;
tmp[n] = location1;
}
fclose(f);
free(lines[0]); // header
qsort(&lines[1], n - 1, sizeof *lines, strcmp2);
for(size_t i = 1; i < n; i++) {
printf("%s\n", lines[i]);
free(lines[i]);
}
free(lines);
}
It produces the expected output:
Theater-District
Upper-East-Side
West-Village
So, assuming some hard limits on line length and CSV file record count, we can just use arrays.
To read a record, just use fgets(). Add each line of text to the array using the usual method.
We use a simple string search and truncate to isolate the first field. (Assuming no fancy stuff like double-quoted fields. I assume you are doing homework.)
To sort everything except the CSV header record, use qsort() with a little additional mathematics.
#include <iso646.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define unused(x) (void)(x)
#define MAX_LINE_LENGTH 100
#define MAX_RECORD_COUNT 100
int main( int argc, char ** argv )
{
unused( argc );
char records[MAX_RECORD_COUNT][MAX_LINE_LENGTH];
size_t record_count = 0;
const char * filename = argv[1];
if (!filename) return 1;
// Read our records from file
FILE * f = fopen( filename, "r" );
if (!f) return 1;
while ((record_count < MAX_RECORD_COUNT)
and fgets( records[record_count], MAX_LINE_LENGTH, f ))
record_count += 1;
fclose( f );
// Truncate the strings to just the first field
for (size_t n = 0; n < record_count; n++)
{
char * p = strchr( records[n], ',' );
if (p) *p = '\0';
}
// Sort everything but the header
if (record_count > 2) // must exist at least two records + header
qsort( records+1, record_count-1, MAX_LINE_LENGTH,
(int (*)( const void *, const void * ))strcmp );
// Print everything but the header
for (size_t n = 1; n < record_count; n++)
printf( "%s\n", records[n] );
return 0;
}
So I am just trying to learn C and have decided to program a simple calendar where you can add events etc. It is working almost perfectly however, when it tries to read from the file containing the information, the first line contains some strange characters : �<�}�U1.
Code is as follows:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void createCalendar(char filename[]) {
FILE *cptr;
cptr = fopen(filename, "w");
char dates[177/sizeof(char)] = "";
for(int i = 1; i < 32; i++) {
char strtowrite[7/sizeof(char)] = "";
sprintf(strtowrite, "%d - \n", i);
strcat(dates, strtowrite);
}
fprintf(cptr, "%s", dates);
fclose(cptr);
}
void addToDay(char filename[], int day, char event[]) {
FILE *cptr;
cptr = fopen(filename, "r");
char *line = NULL;
size_t len = 0;
ssize_t read;
char dates[177/sizeof(char) + strlen(event)/sizeof(char)];
int i = 1;
while ((read = getline(&line, &len, cptr)) != -1) {
if (i==day) {
char strtowrite[7/sizeof(char) + strlen(event)/sizeof(char)];
sprintf(strtowrite, "%d - %s\n", i, event);
strcat(dates, strtowrite);
}
else {
strcat(dates, line);
}
i += 1;
}
printf("%s", dates);
fclose(cptr);
cptr = fopen(filename, "w");
fprintf(cptr, "%s", dates);
fclose(cptr);
}
int main() {
createCalendar("january");
addToDay("january", 12, "event");
}
and the first line of output is: í¬_<89>lU1 - (in the file)
Try this
char dates[177/sizeof(char) + strlen(event)/sizeof(char)] = {0};
in your addToDay function when declaring the dates variable. I think that you do not set the memory there, so there might be some junk in that memory location.
I am writing a program to compare two binary files and plot the first difference. I want to read 16 bytes of data from each file continuously and compare them. For that I am storing 16 bytes from both file into char *buffer1, buffer2. When I print the output I am getting that buffer1 has both the data of file1 and file2.
The code is as follows:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
void printConversion(char *buf1, char *buf2) {
size_t len = strlen(buf1);
char *binary = malloc(len * 8 + 1);
binary[0] = '\0';
for (size_t i = 0; i < len; ++i) {
char ch = buf1[i];
for (int j = 7; j >= 0; --j) {
if (ch & (1 << j)) {
strcat(binary,"1");
} else {
strcat(binary,"0");
}
}
}
printf("File1: %s\t", binary);
free(binary);
printf("File2:");
for (int i = 0; i < sizeof(buf2); i++) {
printf("%x", buf2[i] - '0');
}
}
void fileRead(FILE *fp, char *buf, int count) {
fseek(fp, count, SEEK_SET);
fread(buf, 1, 16, fp);
}
int fileSize(FILE *fp) {
fseek(fp, 0, SEEK_END);
int size = ftell(fp) + 1;
return size;
}
int main(int argc, char *argv[]) {
printf("***Binary File Comparator***\n ");
int count = 0;
int index = 0;
char buffer1[16];
char buffer2[16];
char buffer3[16];
char buffer4[16];
// Invalid Number of Arguments
if (argc < 3 || argc > 3) {
printf("Invalid Number of Arguments\n");
}
FILE *fp1, *fp2;
fp1 = fopen(argv[1], "rb");
int size = fileSize(fp1);
int size1 = size;
fclose(fp1);
while (size > 1) {
fp1 = fopen(argv[1], "rb");
fileRead(fp1, buffer1, count);
fclose(fp1);
fp2 = fopen(argv[2], "rb");
fileRead(fp2, buffer2, count);
if (size1 < count) {
int lastSize = count - size1;
count = count + lastSize;
fclose(fp2);
} else {
count = count+16;
fclose(fp2);
}
**printf("buffer1:%s\tbuffer2:%s\n", buffer1, buffer2)**;
size = size - 16;
int result = strcmp(buffer1, buffer2);
if (result != 0) {
for (int i = 0; i < sizeof(buffer1); i++) {
if (buffer1[i] != buffer2[i]) {
int count1 = (count - 16) + i;
index++;
if (index == 1) {
printf("Byte_Offset:%x\n", count1);
fp1 = fopen(argv[1], "rb");
fileRead(fp1, buffer3, count1);
fclose(fp1);
fp2 = fopen(argv[2], "rb");
fileRead(fp2, buffer4, count1);
fclose(fp2);
printConversion(buffer3, buffer4);
break;
}
} else {
continue;
}
}
}
}
}
I have tried to highlight the printf part that is printing my buffer1 and buffer2
The output is as follows:
buffer1:83867715933586928386771593358692 buffer2:8386771593358692
buffer1:49216227905963264921622790596326 buffer2:4921622790596326
buffer1:40267236116867294026723611686729 buffer2:4026723611686729
buffer1:82306223673529228230622367352922 buffer2:8230622367352922
buffer1:25869679356114222586967935611422 buffer2:2586967935611422
Can anybody help what I am doing wrong. Please point me the error and what optimization changes could be done in code. I am at learning stage your feedback will be very helpful.
You are complicating the task by reading 16 bytes at a time. If the goal is to indicate the first difference, just read one byte at a time from both files with getc() this way:
int compare_files(FILE *fp1, FILE *fp2) {
unsigned long pos;
int c1, c2;
for (pos = 0;; pos++) {
c1 = getc(fp1);
c2 = getc(fp2);
if (c1 != c2 || c1 == EOF)
break;
}
if (c1 == c2) {
printf("files are identical and have %lu bytes\n", pos);
return 0; // files are identical
} else
if (c1 == EOF) {
printf("file1 is included in file2, the first %lu bytes are identical\n", pos);
return 1;
} else
if (c2 == EOF) {
printf("file2 is included in file1, the first %lu bytes are identical\n", pos);
return 2;
} else {
printf("file1 and file2 differ at position %lu: 0x%02X <> 0x%02X\n", pos, c1, c2);
return 3;
}
}
In terms of efficiency, reading one byte at a time does not pose a problem if the streams are buffered. For large files, you can get better performance by memory mapping the file contents if available on the target system and for the given input streams.
Not an actual answer, but a word on optimisation. You can increase the speed of the program if you have a bigger buffer. Basically the larger the buffer the faster the program runs HOWEVER the speed you gain from just making it larger will increase logarithmically.
Here is a picture of a graph that will help you understand. Also, what i mentioned applies to any simmilar situation. This includes: Copying files, filling the sound buffer etc. Loading the entire file in your RAM first and operationg on it will usually be faster than loading parts of it. Ofc this is not possible with larger files but still this is what you should aim for if you want speed.
PS: I'm writting here because i don't have rep to comment.
EDIT: I came up with solution but since you did not state what you need to do with your buffer3 and buffer4 i packed it up inside a function.
If you are sure that you are only going to use 16 bytes as a buffer size, remove the nBufferSize parameter and replace the buffer dynamic allocation with a static one.
If after the execution you need the buffers, add them as parameters and keep the nBufferSize param. Keep in mind that if you intend to use them outside the function, you should also allocate them outside the function, so things don't get messy.
/** Returns 0 if files are identical, 1 if they are different and -1 if there
is an error. */
int FileCmp(char* szFile1, char* szFile2, int nBufferSize)
{
FILE *f1, *f2;
f1 = fopen(szFile1, "rb");
f2 = fopen(szFile2, "rb");
// Some error checking?
if (f1 == NULL || f2 == NULL)
return -1;
// You can check here for file sizes before you start comparing them.
// ...
// Start the comparrison.
/// Replace this part with static allocation. --------
char* lpBuffer1 = malloc(sizeof(char)*nBufferSize);
if (lpBuffer1 == NULL) // close the files and return error.
{
fclose(f1);
fclose(f2);
return -1;
}
char* lpBuffer2 = malloc(sizeof(char)*nBufferSize);
if (lpBuffer2 == NULL) // close the files, free buffer1 and return error.
{
free(lpBuffer1);
fclose(f1);
fclose(f2);
return -1;
}
/// --------------------------------------------------
while(1)
{
unsigned int uRead1 = fread(lpBuffer1, sizeof(char), nBufferSize, f1);
unsigned int uRead2 = fread(lpBuffer2, sizeof(char), nBufferSize, f2);
if (uRead1 != uRead2)
goto lFilesAreDifferent;
for(unsigned int i = 0; i < uRead1; i++)
if (lpBuffer1[i] != lpBuffer2[i])
goto lFilesAreDifferent;
if ((feof(f1) != 0) && (feof(f2) != 0))
break; // both files have nothing more to read and are identical.
goto lSkip;
lFilesAreDifferent:
free(lpBuffer1);
free(lpBuffer2);
fclose(f1);
fclose(f2);
return 1;
lSkip:;
}
// The files are the same. Close them, free the buffers and return 0.
free(lpBuffer1);
free(lpBuffer2);
fclose(f1);
fclose(f2);
return 0;
}
A simple Demo:
#define BUFFER_SIZE 16
int main(int nArgs, char** szArgs)
{
if (nArgs != 3)
{
printf("Invalid number of arguments.");
return 0;
}
int nResult = FileCmp(szArgs[1], szArgs[2], BUFFER_SIZE);
switch (nResult)
{
case 0: printf("Files [%s] and [%s] are identical.", szArgs[1], szArgs[2]); break;
case 1: printf("Files [%s] and [%s] are different.", szArgs[1], szArgs[2]); break;
case -1: printf("Error."); break;
}
return 0;
}
EDIT II: Personally, i have never used the C standard FILE library (it was either C++ fstream or pure win32 fileapi) so don't take my word here for granted but fread is the fastest function i could find (faster than fgets or fgetc). If you want even faster than this you should get into OS dependant functions (like ReadFile() for Windows).
chqrlie's solution using getc is absolutely the right way to do this. I wanted to address some points brought up in comments, and find it's best to do that with code. In one comment, I recommend pseudo code which could be confusing (namely, you can't write fwrite(file1...) || fwrite(file2 ...) because of the short circuit. But you can implement the idea of that with:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/*
* Compare two files, 16 bytes at a time. (Purely to demonstrate memcmp.
* Clearly, this should be implemented with getc.)
*/
FILE * xfopen(const char *, const char *);
size_t xfread(void *, FILE *, const char *);
int
main(int argc, char **argv)
{
FILE *fp[2];
size_t n[2];
char buf[2][16];
unsigned count = 0;
if(argc != 3) { return EXIT_FAILURE; }
fp[0] = xfopen(argv[1], "r");
fp[1] = xfopen(argv[2], "r");
do {
n[0] = xfread(buf[0], fp[0], argv[1]);
n[1] = xfread(buf[1], fp[1], argv[2]);
if( n[0] != n[1] || (n[0] && memcmp(buf[0], buf[1], n[0]))) {
fprintf(stderr, "files differ in block %u\n", count);
return 1;
}
count += 1;
} while(n[0]);
puts("files are identical");
return 0;
}
size_t
xfread(void *b, FILE *fp, const char *name)
{
size_t n = fread(b, 1, 16, fp);
if(n == 0 && ferror(fp)) {
fprintf(stderr, "Error reading %s\n", name);
exit(EXIT_FAILURE);
}
return n;
}
FILE *
xfopen(const char *path, const char *mode)
{
FILE *fp = strcmp(path, "-") ? fopen(path, mode) : stdin;
if( fp == NULL ) {
perror(path);
exit(EXIT_FAILURE);
}
return fp;
}
I've been trying to run this code on VS2017. The code is compiling and running, but not in the way I want it too. So, I try to use the debugger and it says:
Debug Assertion Failed!
Program:
File: minkernel\crts\ucrt\src\appcrt\stdio\fgets.cpp
Line:33
Expression: stream.valid()
From past questions I understood that it may happen because of mishandling the opening of files, but I think that my code does take care of it.
Any help would be greatly appreciated!
(my relevant code):
int main(int argc, char *argv[]) {
int i, count_commands, PC_A, lastLine;
int *PC = &PC_A;
FILE *memin;
FILE *memout;
FILE *regout;
FILE *trace;
FILE *count;
assert(argc == 6);
*PC = 0;
count_commands = 0;
//allocationg memory for registers content
char **regs = (char **)(malloc(sizeof(char *) * 16));
for (i = 0; i < 16; i++) {
regs[i] = (char *)(malloc(sizeof(char) * 9));
for (int j = 0; j < 8; j++) {
regs[i][j] = '0';
}
regs[i][8] = '\0';
}
//allocationg memory for the memory image we have
char **memory = (char **)(malloc(sizeof(char *) * 4096));
for (i = 0; i < 4096; i++) {
memory[i] = (char *)(malloc(sizeof(char) * 9));
memory[i][0] = '\0';
}
//load memin image into memory
char *line = (char *)malloc(sizeof(char) * 8);
memin = fopen(argv[1], "r");
if (memin != NULL) {
perror(strerror(errno));
}
int j = 0;
while ((line = fgets(line, 10, (FILE *)memin)) != NULL) {
strcpy(memory[j], line);
memory[j][8] = '\0';
j++;
}
After opening the file, in OP's code there is this check:
if (memin != NULL) {
perror(strerror(errno));
}
So, if the opening succeeded an error string is printed. In my implementation, it reports:
Success: Success
No action is taken if it fails to open the file.
When it comes to the actual reading of all the lines in the file, there are some other issues. A buffer (char array) named line of size 8 is dinamically allocated and passed to fgets:
while ((line = fgets(line, 10, (FILE *)memin)) != NULL) {
// ^^
Note that 10 is also passed, as size of the buffer, which is wrong, because it allows fgets to write out of the bounds of the allocated array.
Also, given OP's compiler is MSVC 2017, I assume this code is running on Windows, so chances are that in the file, the lines are terminated by a "\r\n" sequence, rather then a single '\n'. Even if OP is confident that each line is a 8 char string, fgets needs a buffer of at least size 8 + 3 (8 + '\r' + '\n' + '\0') to read them safely.
Consider how those suggestions are implemented in this snippet:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#define MEM_SIZE 1024u
#define LINE_SIZE 128u
#define STR_SIZE 8u
int main(int argc, char *argv[])
{
// Try to open the input file
if (argc < 2) {
fprintf(stderr, "Missing file name in command line.\n");
return EXIT_FAILURE;
}
FILE *memin = fopen(argv[1], "r");
if (memin == NULL) {
fprintf(stderr, "Unable to open file [%s].\n", argv[1]);
return EXIT_FAILURE;
}
// I'd use plain arrays to store the lines
char memory[MEM_SIZE][STR_SIZE + 1] = {{'\0'}};
char line[LINE_SIZE] = {'\0'};
size_t count = 0;
while ( count < MEM_SIZE && fgets(line, LINE_SIZE, memin) ) {
size_t length = strcspn(line, "\r\n");
if (length > STR_SIZE) {
fprintf(stdout, "Warning, line too long: %zu.\n", count);
length = STR_SIZE;
}
memcpy(memory[count], line, length);
memory[count][STR_SIZE] = '\0';
++count;
}
for ( size_t i = 0; i < count; ++i ) {
printf("[%s]\n", memory[i]);
}
}
i'm trying to read lines of a file. txt, but without knowing the size of each lines...First I used the getline instruction (and works fine), but my teacher does not let me use that instruction, he says I can only use the fgets statement with malloc and realloc...
This is an input example, with variable line sizes:
[9.3,1.2,87.9]
[1.0,1.0]
[0.0,0.0,1.0]
As shown, each line defines a different vector with no size limit
Someone could help me implement this method?
Thank you very much.
NOTE: I forgot to mention, to compile the program I use these commands:
g++ -Wall-Wextra-Werror-pedantic main.c-o metbasicos.c metintermedios.c eda.exe
./eda.exe <eda.txt
I would say do something similar to this
while(fgets(buf, LEN, stdin)){
z = strtok(buf, ",");
*(*(matrix + i)) = atof(z);
for(j = 1; j < col; ++j){
z = strtok(NULL, ",");
*(*(matrix + i) + j) = atof(z);
}
++i;
}
The only extra thing you would have to take care of is making sure that you strip the brackets off of the first and last element.
Of course, if you don't know the size of the final array, you might need something like this:
struct data_t {
int nval; /* current number of values in array */
int max; /* allocated number of vlaues */
char **words; /* the data array */
};
enum {INIT = 1, GROW = 2};
...
while (fgets(buf, LEN, stdin)) {
if (data->words == NULL)
data->words = malloc(sizeof(char *));
else if (data->nval > data->max) {
data->words = realloc(data->words, GROW * data->max *sizeof(char *));
data->max = GROW * data->max;
}
z = strtok(buf, "\n");
*(data->words + i) = malloc(sizeof(char) * (strlen(z) + 1));
strcpy(*(data->words + i), z);
i++;
data->nval++;
}
data->nval--;
If you combine both of those while loops into a single one, you should be all set. The first one reads in floats, the second one is good for dynamically allocating space on the fly.
If you can use multiple steps, then use one function to get the information you need to malloc memory. (for example determine number of lines, and longest line) This function will do that for you (given the file name and location)
[EDIT] LineCount - This function will get you the number of lines, and the longest line so you can dynamically allocate memory in char **strings; in which to read the lines of the input file.
int lineCount(char *file, int *nLines)
{
FILE *fp;
int cnt=0, longest=0, numLines=0;
char c;
fp = fopen(file, "r");
while ( (c = fgetc ( fp) ) != EOF )
{
if ( c != '\n' )
{
cnt++;
if (cnt > longest) longest = cnt;
}
else
{
numLines++;
cnt= 0;
}
}
*nLines = numLines+1;//add one more
fclose(fp);
return longest+1;
}
Here is the implementation to read the input file you provided, using the function above to get the unknown dimensions of the input file...
#include <ansi_c.h>
#include <stdio.h>
#define FILENAME "c:\\dev\\play\\in.txt" //put your own path here
#define DELIM "- ,:;//_*&[]\n" //change this line as needed for search criteria
int lineCount(char *file, int *cnt);
void allocMemory(int numStrings, int max);
void freeMemory(int numStrings);
char **strings;
int main()
{
int numLines, longest, cnt, i;
FILE *fp;
longest = lineCount(FILENAME, &numLines);
char wordKeep[longest];
allocMemory(numLines, longest);
//read file into string arrays
fp = fopen(FILENAME, "r");
cnt=0;
i=0;
for(i=0;i<numLines;i++)
{
fgets(strings[i], longest, fp);
}
fclose(fp);
freeMemory(numLines);
getchar();
return 0;
}
int lineCount(char *file, int *nLines)
{
FILE *fp;
int cnt=0, longest=0, numLines=0;
char c;
fp = fopen(file, "r");
while ( (c = fgetc ( fp) ) != EOF )
{
if ( c != '\n' )
{
cnt++;
if (cnt > longest) longest = cnt;
}
else
{
numLines++;
cnt= 0;
}
}
*nLines = numLines+1;//add one more
fclose(fp);
return longest+1;
}
void allocMemory(int numStrings, int max)
{
int i;
// need number of lines by longest line for string containers
strings = calloc(sizeof(char*)*(numStrings+1), sizeof(char*));
for(i=0;i<numStrings; i++)
{
strings[i] = calloc(sizeof(char)*max + 1, sizeof(char));
}
}
void freeMemory(int numStrings)
{
int i;
for(i=0;i<numStrings; i++)
if(strings[i]) free(strings[i]);
free(strings);
}