C string print "tmp" instead of the actual string inside it - arrays

Question

I'm trying to display the contents of the directory, I am adding the directory name to the array of strings and printing it, but instead of printing the array the program prints "tmp".
void do_ls(char * dir){
struct dirent * entry;
DIR * dp = opendir(dir);
if(dp == NULL){
fprintf(stderr, "Can not open directory:%s\n", dir);
return;
}
setLenAndNum(dir);
char fileNames[totalNumOfFiles][lenOfLongestFile]; //array to store all file names
int i = 0; //index to iterate through filenames
errno = 0;
while((entry = readdir(dp)) != NULL){
if(entry == NULL && errno != 0){
perror("readdir failed");
exit(errno);
}
else{
if(entry->d_name[0] == '.')
continue;
while(i < totalNumOfFiles){
for(int j=0; j<lenOfLongestFile; j++){
fileNames[i][j] = entry->d_name[j];
}
i++;
}
}
}
i = 0;
while(i < totalNumOfFiles){
printf("%s\n", fileNames[i++]);
}
closedir(dp);
}
This is the function in question, the variables totalNumOfFiles and lenOfLongestFile are global variables and they work correctly I have tested them.

Answer 1

Let's see what we have here... My comments... well, in the comments ;)
void do_ls(char * dir) {
struct dirent *entry;
DIR *dp = opendir(dir);
if (dp == NULL){
fprintf(stderr, "Can not open directory:%s\n", dir);
return;
}
// I don't know what function below does
// I assume it sets totalNumOfFiles and lenOfLongestFile;
setLenAndNum(dir);
char fileNames[totalNumOfFiles][lenOfLongestFile]; //array to store all file names
int i = 0; //index to iterate through filenames
// You don't have to set errno to zero
errno = 0;
while ((entry = readdir(dp)) != NULL) {
// Statement above guarantees that the loop won't be run
// when entry == NULL, so what for is the if statement below?
// It's a dead code. get rid of it.
if (entry == NULL && errno != 0) {
perror("readdir failed");
exit(errno);
} else {
if(entry->d_name[0] == '.')
continue;
// Ok, so here we are with a SINGLE file entry, and with this
// SINGLE file entry you fill the WHOLE table with it.
// This is clearly wrong.
while (i < totalNumOfFiles) {
// Also, you should use a strcpy function to copy string.
// It will copy necessary number of bytes and trailing 0.
for(int j=0; j<lenOfLongestFile; j++){
fileNames[i][j] = entry->d_name[j];
}
i++;
}
}
// So here all rows in the table are filled with the last read
// file name
}
i = 0;
while(i < totalNumOfFiles){
printf("%s\n", fileNames[i++]);
}
closedir(dp);
}
Here is corrected code:
void do_ls(char *dir) {
struct dirent *entry;
DIR *dp = opendir(dir);
if (dp == NULL){
fprintf(stderr, "Can not open directory:%s\n", dir);
return;
}
setLenAndNum(dir);
char fileNames[totalNumOfFiles][lenOfLongestFile]; //array to store all file names
int i = 0; //index to iterate through filenames
while ((entry = readdir(dp)) != NULL) {
if (entry->d_name[0] == '.')
continue;
strcpy(fileNames[i], entry->d_name);
i++;
}
i = 0;
while (i < totalNumOfFiles) {
printf("%s\n", fileNames[i++]);
}
closedir(dp);
}