Thread: Function to Parse a Text field into 100 Character fields

So what separates one field from another?

A comma
A tab
The fact that it's exactly 120 chars wide

I would say a blank since it could be a paragraph as below. In JD Edwards this would be stored in what we call a Media Object it would be 1 continues text field that I would need to parsed into columns, I could have put them in 50, 100, or 120 chars' columns.


Sample:
"Paragraphs are the building blocks of papers. Many students define paragraphs in terms of length: a paragraph is a group of at least five sentences, a paragraph is half a page long, etc. In reality, though, the unity and coherence of ideas among sentences is what constitutes a paragraph. A paragraph is defined as “a group of sentences or a single sentence that forms a unit” (Lunsford and Connors 116). Length and appearance do not determine whether a section in a paper is a paragraph. For instance, in some styles of writing, particularly journalistic styles, a paragraph can be just one sentence long. Ultimately, a paragraph is a sentence or group of sentences that support one main idea. In this handout, we will refer to this as the “controlling idea,” because it controls what happens in the rest of the paragraph."

I don't know about the string types in this API. Assuming they are null-terminated strings of char and also assuming that you just want to divide it into chunks to save it and concatenate it again later on (where it wouldn't even matter if a blank is the separator as long as you keep the maximum length).
Perhaps this gives you an idea of how to achieve it ...

Code:

#include <assert.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


typedef void (*chunk_callback_t)(const char *);
void iterate_chunks(chunk_callback_t chunkproc, const char *string, size_t maxlength);
void print_chunk(const char *chunk);


int main(void)
{
  static const char str[] =
    "Paragraphs are the building blocks of papers. Many students define paragraphs in terms of length: a paragraph is a group of at least five sentences, a paragraph is half a page long, etc. In reality, though, the unity and coherence of ideas among sentences is what constitutes a paragraph. A paragraph is defined as \"a group of sentences or a single sentence that forms a unit\" (Lunsford and Connors 116). Length and appearance do not determine whether a section in a paper is a paragraph. For instance, in some styles of writing, particularly journalistic styles, a paragraph can be just one sentence long. Ultimately, a paragraph is a sentence or group of sentences that support one main idea. In this handout, we will refer to this as the \"controlling idea,\" because it controls what happens in the rest of the paragraph.";


  iterate_chunks(&print_chunk, str, 100);
  return 0;
}


void print_chunk(const char *chunk)
{
  puts(chunk);
}


void iterate_chunks(chunk_callback_t chunkproc, const char *string, size_t maxlength)
{
  assert(chunkproc);
  assert(string);
  assert(maxlength);


  const size_t totalchars = strlen(string);
  if (!totalchars)
    return;


  char *buffer = malloc(maxlength + 1);
  assert(buffer);


  buffer[maxlength] = '\0';
  const size_t nchunks = totalchars / maxlength;
  const size_t nchars = nchunks * maxlength;
  const size_t remchars = totalchars - nchars;


  if (nchunks)
    for (const char *cursor = string, *const end = cursor + nchars; cursor < end; cursor += maxlength)
      chunkproc((const char *)memcpy(buffer, cursor, maxlength));


  if (remchars)
    chunkproc((const char *)memcpy(buffer, string + nchars, remchars + 1));


  free(buffer);
}

Like any of these?

Code:

$ xsel | fold -w 50
Paragraphs are the building blocks of papers. Many
 students define paragraphs in terms of length: a 
paragraph is a group of at least five sentences, a
 paragraph is half a page long, etc. In reality, t
hough, the unity and coherence of ideas among sent
ences is what constitutes a paragraph. A paragraph
 is defined as “a group of sentences or a single
 sentence that forms a unit” (Lunsford and Conno
rs 116). Length and appearance do not determine wh
ether a section in a paper is a paragraph. For ins
tance, in some styles of writing, particularly jou
rnalistic styles, a paragraph can be just one sent
ence long. Ultimately, a paragraph is a sentence o
r group of sentences that support one main idea. I
n this handout, we will refer to this as the “co
ntrolling idea,” because it controls what happen
s in the rest of the paragraph.

$ xsel | fold -w 100
Paragraphs are the building blocks of papers. Many students define paragraphs in terms of length: a 
paragraph is a group of at least five sentences, a paragraph is half a page long, etc. In reality, t
hough, the unity and coherence of ideas among sentences is what constitutes a paragraph. A paragraph
 is defined as “a group of sentences or a single sentence that forms a unit” (Lunsford and Conno
rs 116). Length and appearance do not determine whether a section in a paper is a paragraph. For ins
tance, in some styles of writing, particularly journalistic styles, a paragraph can be just one sent
ence long. Ultimately, a paragraph is a sentence or group of sentences that support one main idea. I
n this handout, we will refer to this as the “controlling idea,” because it controls what happen
s in the rest of the paragraph.

$ xsel | fold -w 120
Paragraphs are the building blocks of papers. Many students define paragraphs in terms of length: a paragraph is a group
 of at least five sentences, a paragraph is half a page long, etc. In reality, though, the unity and coherence of ideas 
among sentences is what constitutes a paragraph. A paragraph is defined as “a group of sentences or a single sentence 
that forms a unit” (Lunsford and Connors 116). Length and appearance do not determine whether a section in a paper is 
a paragraph. For instance, in some styles of writing, particularly journalistic styles, a paragraph can be just one sent
ence long. Ultimately, a paragraph is a sentence or group of sentences that support one main idea. In this handout, we w
ill refer to this as the “controlling idea,” because it controls what happens in the rest of the paragraph.

But there's no regard for punctuation or natural word breaks.
It literally just chops the input at a given number of characters.

If that's good, all you need is the size of buffer you want, and fgets/fread in a loop.

It's all very vague.

We have an expected input, but no idea about the output.