I need an input with strings in C

Question

i need to read strings from file in C, and that's work, now i need to find in each string the words that start with a capital letter. Any input?

Example: 1) Windows is a good OS 2) Linux is Open Source

Words with capital letter: Windows, OS, Linux, Open, Source.

#include <stdio.h>

int main()
{
  /* dichiarazioni variabili */

  FILE *fp;
  char vet1[100];
  char vet2[100];

  fp = fopen("file.txt", "r"); /* apro il file contenente la stringa */

  if (fp == NULL) {
    printf("\nIl file non esiste!\n");
  }

  while (!feof(fp)) {
    fgets(vet1, 100, fp);
    printf("%s\n", vet1);
  }

  fclose(fp);
}

Welcome to SO. What code have you written to try to solve this problem yourself? — Sean, Mar 28 '19 at 15:42
I thought of taking the vector containing the string and comparing the first letter with the next, as soon as it recognizes the capital letter, it writes the word that contains it. — Max Red, Mar 28 '19 at 15:47
So, i'll write something like this: vet1[pos]>='A' && vet2[pos]<='Z' and with a cicle for I scroll the vector and compare — Max Red, Mar 28 '19 at 15:49
You should try your idea and if it's not working, post the code here. Then we can have a look and see what might be wrong. But don't expect us to write the whole code for you. — ush189, Mar 28 '19 at 15:49
you could use regular expressions : http://man7.org/linux/man-pages/man3/regex.3.html — user3469811, Mar 28 '19 at 16:27
[`while (!feof(fp))`](https://stackoverflow.com/questions/5431941/why-is-while-feoffile-always-wrong) is always wrong — Antti Haapala -- Слава Україні, Mar 28 '19 at 17:16

Miguel Ángel Retamozo Sanchez · Answer 1 · 2019-03-28T17:21:09.003

1

Detect a Capital letter is as simple as read the "ascii" manual in any GNU / Linux distro where you can find that all capital tetters from A to Z has a hex number from 0x40 to 0x5A respectivily with this in mind:

#include <stdio.h>
#include <stdlib.h>


int main( int argc,char *argv[])
{
  char *buffer,c;
  size_t bufsize = 32; // add all the buffer that you need
  size_t characters;
  FILE *fp;
  if(argc != 2)
    return -1;
  buffer = (char *)malloc(bufsize * sizeof(char));
  fp = fopen(argv[1],"r");
  if( fp == NULL)
     return -2;
  while( !feof(fp) )
  {
    characters = getline(&buffer,&bufsize,fp);
    buffer[characters-1]='\0';
    if ( buffer[0] > 0x40 && buffer[0] < 0x5A )
        printf("buffer = %s",buffer);
  }

  return 0;
}

edited Mar 28 '19 at 17:21

answered Mar 28 '19 at 16:27

Miguel Ángel Retamozo Sanchez

343
4
16

What is this: if(argv[1][0] == '\0') ? And Malloc function (?) P.S: Thank's a lot!! PPS: I can't use stdlib.h library. – Max Red Mar 28 '19 at 17:05
argv[1][0] is the first char of argv[1] and '\0' is the null termination caracter like simple NULL and if(argv[1][0] == '\0') is to be sure that need a file as input. Glad I could help. Feel free to [accept this answer](https://stackoverflow.com/help/accepted-answer) if you found it useful. – Miguel Ángel Retamozo Sanchez Mar 28 '19 at 17:15
1

Your argv construct is just bad. If you want to determine the existence of command line arguments use argc. – dtell Mar 28 '19 at 17:18
@datell thanks for your recomentation I've just edited . – Miguel Ángel Retamozo Sanchez Mar 28 '19 at 17:21

I need an input with strings in C

1 Answers1