#include "f2c.h"

#include "fio.h"

/* Compile this with -DNO_TRUNCATE if unistd.h does not exist or */

/* if it does not define int truncate(const char *name, off_t). */

#ifdef MSDOS

#undef NO_TRUNCATE

#define NO_TRUNCATE

#endif

#ifndef NO_TRUNCATE

#include "unistd.h"

#endif

#ifdef KR_headers

extern char *strcpy();

extern FILE *tmpfile();

#else

#undef abs

#undef min

#undef max

#include "stdlib.h"

#include "string.h"

#ifdef __cplusplus

extern "C" {

#endif

#endif

extern char *f__r_mode[], *f__w_mode[];

#ifdef KR_headers

integer f_end(a) alist *a;

#else

integer f_end(alist *a)

#endif

{

  unit *b;

  FILE *tf;

  if(a->aunit>=MXUNIT || a->aunit<0) err(a->aerr,101,"endfile");

  b = &f__units[a->aunit];

  if(b->ufd==NULL) {

    char nbuf[10];

    sprintf(nbuf,"fort.%ld",(long)a->aunit);

    if (tf = FOPEN(nbuf, f__w_mode[0]))

      fclose(tf);

    return(0);

    }

  b->uend=1;

  return(b->useek ? t_runc(a) : 0);

}

#ifdef NO_TRUNCATE

 static int

#ifdef KR_headers

copy(from, len, to) FILE *from, *to; register long len;

#else

copy(FILE *from, register long len, FILE *to)

#endif

{

  int len1;

  char buf[BUFSIZ];

  while(fread(buf, len1 = len > BUFSIZ ? BUFSIZ : (int)len, 1, from)) {

    if (!fwrite(buf, len1, 1, to))

      return 1;

    if ((len -= len1) <= 0)

      break;

    }

  return 0;

  }

#endif /* NO_TRUNCATE */

 int

#ifdef KR_headers

t_runc(a) alist *a;

#else

t_runc(alist *a)

#endif

{

  OFF_T loc, len;

  unit *b;

  int rc;

  FILE *bf;

#ifdef NO_TRUNCATE

  FILE *tf;

#endif

  b = &f__units[a->aunit];

  if(b->url)

    return(0); /*don't truncate direct files*/

  loc=FTELL(bf = b->ufd);

  FSEEK(bf,(OFF_T)0,SEEK_END);

  len=FTELL(bf);

  if (loc >= len || b->useek == 0)

    return(0);

#ifdef NO_TRUNCATE

  if (b->ufnm == NULL)

    return 0;

  rc = 0;

  fclose(b->ufd);

  if (!loc) {

    if (!(bf = FOPEN(b->ufnm, f__w_mode[b->ufmt])))

      rc = 1;

    if (b->uwrt)

      b->uwrt = 1;

    goto done;

    }

  if (!(bf = FOPEN(b->ufnm, f__r_mode[0]))

   || !(tf = tmpfile())) {

#ifdef NON_UNIX_STDIO

 bad:

#endif

    rc = 1;

    goto done;

    }

  if (copy(bf, (long)loc, tf)) {

 bad1:

    rc = 1;

    goto done1;

    }

  if (!(bf = FREOPEN(b->ufnm, f__w_mode[0], bf)))

    goto bad1;

  rewind(tf);

  if (copy(tf, (long)loc, bf))

    goto bad1;

  b->uwrt = 1;

  b->urw = 2;

#ifdef NON_UNIX_STDIO

  if (b->ufmt) {

    fclose(bf);

    if (!(bf = FOPEN(b->ufnm, f__w_mode[3])))

      goto bad;

    FSEEK(bf,(OFF_T)0,SEEK_END);

    b->urw = 3;

    }

#endif

done1:

  fclose(tf);

done:

  f__cf = b->ufd = bf;

#else /* NO_TRUNCATE */

  if (b->urw & 2)

    fflush(b->ufd); /* necessary on some Linux systems */

#ifndef FTRUNCATE

#define FTRUNCATE ftruncate

#endif

  rc = FTRUNCATE(fileno(b->ufd), loc);

  /* The following FSEEK is unnecessary on some systems, */

  /* but should be harmless. */

  FSEEK(b->ufd, (OFF_T)0, SEEK_END);

#endif /* NO_TRUNCATE */

  if (rc)

    err(a->aerr,111,"endfile");

  return 0;

  }

#ifdef __cplusplus

}

#endif