How to read specific words from a file? - c

Question

I have a file that contains words and their synonyms each on a separate line.
I am writing this code that should read the file line by line then display it starting from the second word which is the synonym.
I used the variable count in the first loop in order to be able to count the number of synonyms of each word because the number of synonyms differs from one to another. Moreover I used the condition synonyms[i]==',' because each synonym is separate by a comma.
The purpose of me writing such code is to put them in a binary search tree in order to have a full dictionary.
The code doesn't contain any error yet it is not working.
I have tried to each the loop but that didn't work too.
Sample input from the file:
abruptly - dead, short, suddenly
acquittance - release
adder - common, vipera
Sample expected output:
dead short suddenly
acquittance realse
common vipera
Here is the code:
void LoadFile(FILE *fp){
int count;
int i;
char synonyms[50];
char word[50];
while(fgets(synonyms,50,fp)!=NULL){
for (i=0;i<strlen(synonyms);i++)
if (synonyms[i]==',' || synonyms[i]=='\n')
count++;
}
while(fscanf(fp,"%s",word)==1){
for(i=1;i<strlen(synonyms);i++){
( fscanf(fp,"%s",synonyms)==1);
printf("%s",synonyms);
}
}
}
int main(){
char fn[]="C:/Users/CLICK ONCE/Desktop/Semester 4/i2206/Project/Synonyms.txt";
FILE *fp;
fp=fopen(fn,"rt");
if (fp==NULL){
printf("Cannot open this file");
}
else{
LoadFile(fp);
}
return 0;
}

Answer 1

Here is my solution. I have split the work into functions for readability. The actual parsing is done in parsefunction. That function thakes into account hyphenated compound words such as seventy-two. The word and his synonyms must be separated by an hyphen preceded by at least one space.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
// Trim leading and trailing space characters.
// Warning: string is modified
char* trim(char* s) {
char* p = s;
int l = strlen(p);
while (isspace(p[l - 1])) p[--l] = 0;
while (*p && isspace(*p)) ++p, --l;
memmove(s, p, l + 1);
return s;
}
// Warning: string is modified
int parse(char* line)
{
char* token;
char* p;
char* word;
if (line == NULL) {
printf("Missing input line\n");
return 0;
}
// first find the word delimiter: an hyphen preceded by a space
p = line;
while (1) {
p = strchr(p, '-');
if (p == NULL) {
printf("Missing hypen\n");
return 0;
}
if ((p > line) && (p[-1] == ' ')) {
// We found an hyphen preceded by a space
*p = 0; // Replace by nul character (end of string)
break;
}
p++; // Skip hyphen inside hypheneted word
}
word = trim(line);
printf("%s ", word);
// Next find synonyms delimited by a coma
char delim[] = ", ";
token = strtok(p + 1, delim);
while (token != NULL) {
printf("%s ", token);
token = strtok(NULL, delim);
}
printf("\n");
return 1;
}
int LoadFile(FILE* fp)
{
if (fp == NULL) {
printf("File not open\n");
return 0;
}
int ret = 1;
char str[1024]; // Longest allowed line
while (fgets(str, sizeof(str), fp) != NULL) {
str[strcspn(str, "\r\n")] = 0; // Remove ending \n
ret &= parse(str);
}
return ret;
}
int main(int argc, char *argv[])
{
FILE* fp;
char* fn = "Synonyms.txt";
fp = fopen(fn, "rt");
if (fp == NULL) {
perror(fn);
return 1;
}
int ret = LoadFile(fp);
fclose(fp);
return ret;
}

Answer 2

I think the biggest conceptual misunderstanding demonstrated in the code is a failure to understand how fgets and fscanf work.
Consider the following lines of code:
while(fgets(synonyms,50,fp)!=NULL){
...
while(fscanf(fp,"%49s",word)==1){
for(i=1;i<strlen(synonyms);i++){
fscanf(fp,"%49s",synonyms);
printf("%s",synonyms);
}
}
}
The fgets reads one line of the input. (Unless there is an input line that is greater than 49 characters long (48 + a newline), in which case fgets will only read the first 49 characters. The code should check for that condition and handle it.) The next fscanf then reads a word from the next line of input. The first line is effectively being discarded! If the input is formatted as expected, the 2nd scanf will read a single - into synonyms. This makes strlen(synonyms) evaluate to 1, so the for loop terminates. The while scanf loop then reads another word, and since synonyms still contains a string of length 1, the for loop is never entered. while scanf then proceeds to read the rest of the file. The next call to fgets returns NULL (since the fscanf loop has read to the end of the file) so the while/fgets loop terminates after 1 iteration.
I believe the intention was for the scanfs inside the while/fgets to operate on the line read by fgets. To do that, all the fscanf calls should be replaced by sscanf.