Trying to scan in user input after the '<' not working on gcc.

I am reading in a csv file, outputting a txt file and also reading in a text file to search for the keys that I have to output into the txt file.

So basically this is my code.
/* This is to read in the CSV file" */

Code:

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while(fscanf(Data_input,"%d; %[^\n]",&weight,num) == 2){       
                insert(ptr,word,num);
        }

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/*Now I want to read in the search key where read_word is declared as char array of size 500*/

Code:

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while(scanf("%[^\n]", read_word) == 1){
        printf("%s\n", read_word);
    }

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The command on stdin should look like this after compilation

./aout read.csv out.txt < search.txt

I am unable to read the search.txt. I tried using fscanf and now I am trying to use just scanf to see if anything happens but the command reads out null as there is no such this that exists on argv[4]? I know its not reading in the file since when I print it out it prints null and exits =(

./aout read.csv out.txt < search.txt
Out.txt is read by fopen on argv [1] and using the resulting file handle in fscanf etc
Search.txt is read simply by doing scanf, because that's now just stdin.

Ok so then right now my code is

Code:

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while(scanf("%[^\n]", read_word) == 1){        printf("%s\n", read_word);
    }

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But is waiting for user input where it should just read it after < search.txt.
So its not reading in the search.txt for some unknown reason

You have to skip \n that was not read by [^\n] format to go to the next line

Code:

---

#include<stdio.h>

int main() {
    char read_word[500];
    int res;
    int read =0;
    while((res = scanf("%499[^\n]\n", read_word)) == 1) {
        printf("%s\n", read_word);
        read++;
    }
    printf("Read=%d, res=%d\n", read, res);
}

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Output

Code:

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$ ./test < test.txt
ATHROCYTES
DISHLIKE
IRRECOVERABLENESSES
EMBRITTLEMENTS
YOUNGS
OVERPLOTS
FED
SQUALLS
SKINFULS
CANNAS
COUNTERGUERILLAS
FINIAL
VACATIONERS
WINTRINESSES
...and so on...
Read=15, res=-1

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