csv.c

/* csv - read write comma separated value format
 * Copyright (c) 2003 Michael B. Allen <mba2000 ioplex.com>
 *
 * The MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <wchar.h>
#include <wctype.h>

#include "mba/msgno.h"
#include "mba/csv.h"

#define ST_START     1
#define ST_COLLECT   2
#define ST_TAILSPACE 3
#define ST_END_QUOTE 4

struct sinput {
  FILE *in;
  const unsigned char *src;
  size_t sn;
  size_t count;
};
struct winput {
  const wchar_t *src;
  size_t sn;
  size_t count;
};

static int
snextch(struct sinput *in)
{
  int ch;

  if (in->in) {
    if ((ch = fgetc(in->in)) == EOF) {
      if (ferror(in->in)) {
        PMNO(errno);
        return -1;
      }
      return 0;
    }
  } else {
    if (in->sn == 0) {
      return 0;
    }
    ch = *(in->src)++;
    in->sn--;
  }
  in->count++;

  return ch;
}
static int
wnextch(struct winput *in)
{
  int ch;

  if (in->sn == 0) {
    return 0;
  }
  ch = *(in->src)++;
  in->sn--;
  in->count++;

  return ch;
}

static int
csv_parse_str(struct sinput *in,
      unsigned char *buf,
      size_t bn,
      unsigned char *row[],
      int rn,
      int sep,
      int flags)
{
  int trim, quotes, ch, state, r, j, t, inquotes;

  trim = flags & CSV_TRIM;
  quotes = flags & CSV_QUOTES;
  state = ST_START;
  inquotes = 0;
  ch = r = j = t = 0;

  memset(row, 0, sizeof(unsigned char *) * rn);

  while (rn && bn && (ch = snextch(in)) > 0) {
    switch (state) {
      case ST_START:
        if (ch != '\n' && ch != sep && isspace(ch)) {
          if (!trim) {
            buf[j++] = ch; bn--;
            t = j;
          }
          break;
        } else if (quotes && ch == '"') {
          j = t = 0;
          state = ST_COLLECT;
          inquotes = 1;
          break;
        }
        state = ST_COLLECT;
      case ST_COLLECT:
        if (inquotes) {
          if (ch == '"') {
            state = ST_END_QUOTE;
            break;
          }
        } else if (ch == sep || ch == '\n') {
          row[r++] = buf; rn--;
          if (ch == '\n' && t && buf[t - 1] == '\r') {
            t--; bn++; /* crlf -> lf */
          }
          buf[t] = '\0'; bn--;
          buf += t + 1;
          j = t = 0;
          state = ST_START;
          inquotes = 0;
          if (ch == '\n') {
            rn = 0;
          }
          break;
        } else if (quotes && ch == '"') {
          PMNF(errno = EILSEQ, ": unexpected quote in element %d", (r + 1));
          return -1;
        }
        buf[j++] = ch; bn--;
        if (!trim || isspace(ch) == 0) {
          t = j;
        }
        break;
      case ST_TAILSPACE:
      case ST_END_QUOTE:
        if (ch == sep || ch == '\n') {
          row[r++] = buf; rn--;
          buf[j] = '\0'; bn--;
          buf += j + 1;
          j = t =  0;
          state = ST_START;
          inquotes = 0;
          if (ch == '\n') {
            rn = 0;
          }
          break;
        } else if (quotes && ch == '"' && state != ST_TAILSPACE) {
          buf[j++] = '"'; bn--;    /* nope, just an escaped quote */
          t = j;
          state = ST_COLLECT;
          break;
        } else if (isspace(ch)) {
          state = ST_TAILSPACE;
          break;
        }
        errno = EILSEQ;
        PMNF(errno, ": bad end quote in element %d", (r + 1));
        return -1;
    }
  }
  if (ch == -1) {
    AMSG("");
    return -1;
  }
  if (bn == 0) {
    PMNO(errno = E2BIG);
    return -1;
  }
  if (rn) {
    if (inquotes && state != ST_END_QUOTE) {
      PMNO(errno = EILSEQ);
      return -1;
    }
    row[r] = buf;
    buf[t] = '\0';
  }

  return in->count;
}
static int
csv_parse_wcs(struct winput *in, wchar_t *buf, size_t bn, wchar_t *row[], int rn, wint_t sep, int flags)
{
  int trim, quotes, state, r, j, t, inquotes;
  wint_t ch;

  trim = flags & CSV_TRIM;
  quotes = flags & CSV_QUOTES;
  state = ST_START;
  inquotes = 0;
  ch = r = j = t = 0;

  memset(row, 0, sizeof(wchar_t *) * rn);

  while (rn && bn && (ch = wnextch(in)) > 0) {
    switch (state) {
      case ST_START:
        if (ch != L'\n' && ch != sep && iswspace(ch)) {
          if (!trim) {
            buf[j++] = ch; bn--;
            t = j;
          }
          break;
        } else if (quotes && ch == L'"') {
          j = t = 0;
          state = ST_COLLECT;
          inquotes = 1;
          break;
        }
        state = ST_COLLECT;
      case ST_COLLECT:
        if (inquotes) {
          if (ch == L'"') {
            state = ST_END_QUOTE;
            break;
          }
        } else if (ch == sep || ch == L'\n') {
          row[r++] = buf; rn--;
          buf[t] = L'\0'; bn--;
          buf += t + 1;
          j = t = 0;
          state = ST_START;
          inquotes = 0;
          if (ch == L'\n') {
            rn = 0;
          }
          break;
        } else if (quotes && ch == L'"') {
          PMNF(errno = EILSEQ, ": unexpected quote in element %d", (r + 1));
          return -1;
        }
        buf[j++] = ch; bn--;
        if (!trim || iswspace(ch) == 0) {
          t = j;
        }
        break;
      case ST_TAILSPACE:
      case ST_END_QUOTE:
        if (ch == sep || ch == L'\n') {
          row[r++] = buf; rn--;
          buf[j] = L'\0'; bn--;
          buf += j + 1;
          j = t =  0;
          state = ST_START;
          inquotes = 0;
          if (ch == L'\n') {
            rn = 0;
          }
          break;
        } else if (quotes && ch == L'"' && state != ST_TAILSPACE) {
          buf[j++] = L'"'; bn--;     /* nope, just an escaped quote */
          t = j;
          state = ST_COLLECT;
          break;
        } else if (iswspace(ch)) {
          state = ST_TAILSPACE;
          break;
        }
        PMNF(errno = EILSEQ, ": bad end quote in element %d", (r + 1));
        return -1;
    }
  }
  if (ch == (wint_t)-1) {
    AMSG("");
    return -1;
  }
  if (bn == 0) {
    PMNO(errno = E2BIG);
    return -1;
  }
  if (rn) {
    if (inquotes && state != ST_END_QUOTE) {
      PMNO(errno = EILSEQ);
      return -1;
    }
    row[r] = buf;
    buf[t] = L'\0';
  }

  return in->count;
}
int
csv_row_parse_wcs(const wchar_t *src, size_t sn, wchar_t *buf, size_t bn, wchar_t *row[], int rn, int sep, int trim)
{
  struct winput input;
  input.src = src;
  input.sn = sn;
  input.count = 0;
  return csv_parse_wcs(&input, buf, bn, row, rn, (wint_t)sep, trim);
}
int
csv_row_parse_str(const unsigned char *src, size_t sn, unsigned char *buf, size_t bn, unsigned char *row[], int rn, int sep, int trim)
{
  struct sinput input;
  input.in = NULL;
  input.src = src;
  input.sn = sn;
  input.count = 0;
  return csv_parse_str(&input, buf, bn, row, rn, sep, trim);
}
int
csv_row_fread(FILE *in, unsigned char *buf, size_t bn, unsigned char *row[], int numcols, int sep, int trim)
{
  struct sinput input;
  input.in = in;
  input.count = 0;
  return csv_parse_str(&input, buf, bn, row, numcols, sep, trim);
}