Simple and fast CSV reader written in C

Description

Simple and fast library for fast reading of large CSV files using memory-mapped files.
Purpose of this project was to create fast CSV (comma separated values) reader implementation in C with very simple interface using memory-mapped files.

Features

• Simple C interface
• Very large CSV file support - GBs, TBs
• Using memory mapped files
• Supports UNIX and Windows platforms
• UTF-8 support
• Supports both Windows CRLF “\r\n” and Unix LF “\n” sequences
• Supports newlines “\n” in CSV columns
• Spaces are preserved (e.g “one, two” -> {“one”, " two"})

How to compile

You can add csv.c file to your project or you can use Makefile provided.
To compile csv library on Linux with GNU Make:

• run make all from project root to compile all targets and test application

How to use (trivial example)

Error handing ommited for brevity

char* row;
int cols = 0;
CsvHandle handle = CsvOpen("csvfile.csv");

while (row = CsvReadNextRow(handle))
{
    /* row = CSV row string */
    const char* col;
    while (col = CsvReadNextCol(row, handle))
        cols++;  /* col = CSV col string */
}

printf("Number of cols %i", cols);

Public API functions

If you want to read classic CSV files, you can follow this pipeline:

1. CsvOpen() to open CSV file
2. CsvReadNextRow() to read single CSV line
3. CsvReadNextCol() to read single CSV column
4. CsvClose() to close opened CSV handle

CsvOpen(const char* filepath)

Opens a CSV file.

Paramters:

• filepath, (const char*): path to a CSV file

Return value:

CsvHandle: handle to a CSV file on success, NULL otherwise

CsvOpen2(const char* filepath, char delim, char quote, char escape)

Opens a CSV file. You can specify custom CSV delimeter, quote and escape char.

Parameters:

• filepath, (const char*): path to a CSV file
• delim (char): custom CSV delimeter ASCII character (default ‘,’)
• quote (char): custom CSV quote ASCII character (default ‘"’)
• escape (char): custom CSV escape ASCII character (default ‘\’)

Return value:

CsvHandle: handle to a CSV file on success, NULL otherwise

CsvClose(CsvHandle handle)

Releases all resources allocated.

Parameters:

• handle (CsvHandle): handle opened by CsvOpen() or CsvOpen2()

CsvReadNextRow(CsvHandle handle)

Returns pointer to new line (UTF-8 zero terminated string) or NULL.

Parameters:

• handle (CsvHandle): handle opened by CsvOpen() or CsvOpen2()

Return value:

char*: zero terminated string on success, NULL on EOF or error.

CsvReadNextCol(CsvHandle handle, char* row)

Returns pointer to column (UTF-8 zero terminated string) or NULL

Parameters:

• handle (CsvHandle): handle opened by CsvOpen() or CsvOpen2()

Return value

const char*: zero terminated string on success, NULL on EOL or error.

License

MIT (see LICENSE.txt)