Question

First and foremost, I am not asking anyone to write a program for me or to do my homework for me… I have an error and I can’t figure out what’s causing it, and where to look to fix it.

So I’m attempting to create a program that will take a command and an input file from the command line, and, based on the command selection, perform one of several functions: either coutn the lines of the input file, count the words of the input file, or check the input file for palindromes and then compare the palindromes (if any) to a dictionary file.

Here is the code as it stands:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>

void usage(char *prog_name) //usage file if input format is wrong
{
    printf("Usage: %s, <-h>|<-l>|<-w>|<-p>, <filename>\n", prog_name);
    exit(0);
}

void help(char *prog_name, char *filename) //help file for -h option
{
    printf("Welcome to the help file\n");
    printf("For number of lines, enter: <%s>, <-l>, <%s>.\n", prog_name, filename);
    printf("For number of words, enter: <%s>, <-w>, <%s>.\n", prog_name, filename);
    printf("To list the palindromes in alphabetical order, print the number of
    palindromes, and to check them against the dictionary, enter: <%s>, <-p>, <%s>\n",
    prog_name, filename);
    exit(0);
}

void fatal(char *);  //function for fatal errors
void *ec_malloc(unsigned int);  //error-checked malloc wrapper

void linecount(char *filename)  // counts the number of lines of input file
{
    char *infile;
    infile = (char *) ec_malloc(strlen(filename));
    strcpy(infile, filename);
    FILE *fp = fopen(infile, "r");

    if (fp == NULL)         
         fatal("input file does not exist");

    int ch;
    int count = 0;                                  

    do {             
    ch = fgetc(fp);
    if( ch== '\n')
            count++;
    }   
    while( ch != EOF );                                 

    printf("Total number of lines %d\n",count);
    exit(0);            
}

int main(int argc, char *argv[])
{
    if (argc < 3) //if there aren't enough arguments, display the usage file
    {
            usage(argv[0]);
    }
    else if (argv[1] == "-h") //this is the help option
    {
        help(argv[0], argv[2]);
    }
    else if (argv[1] == "-l") //this is the line count option
    {
        linecount(argv[2]);
    }
    else
    {

            fatal("skipped if functions");
    }
    return 0;
}
void fatal(char *message) //this function displays an error message and then exits
{   
    char error_message[100];
    strcpy(error_message, "[!!] Fatal Error ");
    strncat(error_message, message, 83);
    perror(error_message);
    exit(-1);
}

void *ec_malloc(unsigned int size) //wrapper function for an error checked malloc
{
    void *ptr;
    ptr = malloc(size);

    if(ptr == NULL)
        fatal("in ec_malloc() on memory allocation");

    return ptr;
}   

So, when I run:

gcc -o fr filereader.c

./fr -h fevbwervrwe.txt

I get the error message stating that the if statements were skipped.

Same if I try running

./fr -l vrweqvervvq.txt

It seems the compiler is skipping over my if statements, and I honestly can’t figure out why. Any help at all would be greatly appreciated.

Answer 1

Try strcmp() instead of ==.