How to Read All File Bytes into a Character Array in C ?

Retrieving All File Bytes into a Character Array in C

This question seeks to understand how to read the contents of a file into a character array, bypassing the limitations of getline().

Solution:

Instead of using getline(), consider implementing ifstream::read() for reading a file as a stream of bytes. The following steps outline the process:

1. Opening the File:

<code class="cpp">std::ifstream infile("C:\MyFile.csv"); // consider std::ios_base::binary for binary reads</code>

2. Determining File Length:

<code class="cpp">infile.seekg(0, std::ios::end);
size_t length = infile.tellg();
infile.seekg(0, std::ios::beg);</code>

3. Buffer Overflow Prevention:

<code class="cpp">if (length > sizeof(buffer)) {
    length = sizeof(buffer);
}</code>

4. Reading the File:

<code class="cpp">infile.read(buffer, length);</code>

Additional Notes:

• Using seekg() and tellg() to determine file size is not guaranteed to be exact but usually works.
• Opening the file in non-binary mode may result in character translations that affect the resulting buffer size.
• For single-shot file reading, Remy Lebeau's answer recommends using std::vector and std::istreambuf_iterator for improved efficiency.
• In case of buffered reads, consider using gcount() to track the actual number of characters read.

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