pico/fileio.c

   1 /*
   2  * ========================================================================
   3  * Copyright 2006 University of Washington
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * ========================================================================
  12  *
  13  * Program:     file reading routines
  14  *
  15  */
  16
  17 /*
  18  * The routines in this file read and write ASCII files from the disk. All of
  19  * the knowledge about files are here. A better message writing scheme should
  20  * be used.
  21  */
  22 #include        "headers.h"
  23 #include        "../pith/charconv/filesys.h"
  24
  25
  26 #if     defined(bsd) || defined(lnx)
  27 #ifndef errno
  28 extern int errno;
  29 #endif
  30 #endif
  31
  32
  33
  34 FIOINFO g_pico_fio;
  35
  36 /*
  37  * Open a file for reading.
  38  */
  39 int
  40 ffropen(char *fn)
  41 {
  42     int status;
  43
  44     if ((status = fexist(g_pico_fio.name = fn, "r", (off_t *)NULL)) == FIOSUC){
  45         g_pico_fio.flags = FIOINFO_READ;
  46         if((g_pico_fio.fp = our_fopen(g_pico_fio.name, "r")) == NULL)
  47           status = FIOFNF;
  48     }
  49
  50     return (status);
  51 }
  52
  53
  54 /*
  55  * Write a line to the already opened file. The "buf" points to the buffer,
  56  * and the "nbuf" is its length, less the free newline. Return the status.
  57  * Check only at the newline.
  58  */
  59 int
  60 ffputline(CELL buf[], int nbuf)
  61 {
  62     register int    i;
  63     EML eml;
  64
  65     for(i = 0; i < nbuf; ++i)
  66        if(write_a_wide_char((UCS) buf[i].c, g_pico_fio.fp) == EOF)
  67          break;
  68
  69    if(i == nbuf)
  70      write_a_wide_char((UCS) '\n', g_pico_fio.fp);
  71
  72     if(ferror(g_pico_fio.fp)){
  73         eml.s = errstr(errno);
  74         emlwwrite(_("Write error: %s"), &eml);
  75         sleep(5);
  76         return FIOERR;
  77     }
  78
  79     return FIOSUC;
  80 }
  81
  82
  83 /*
  84  * Read a line from a file, and store the bytes in the supplied buffer. The
  85  * "nbuf" is the length of the buffer. Complain about long lines and lines
  86  * at the end of the file that don't have a newline present. Check for I/O
  87  * errors too. Return status.
  88  *
  89  * Translate the line from the user's locale charset to UCS-4.
  90  */
  91 int
  92 ffgetline(UCS buf[], size_t nbuf, size_t *charsreturned, int msg)
  93 {
  94     size_t i;
  95     UCS    ucs;
  96     static int displayed = 0;
  97
  98     if(charsreturned)
  99       *charsreturned = 0;
 100
 101     i = 0;
 102
 103     while((ucs = read_a_wide_char(g_pico_fio.fp, input_cs)) != CCONV_EOF && ucs != '\n'){
 104         /*
 105          * Don't blat the CR should the newline be CRLF and we're
 106          * running on a unix system.  NOTE: this takes care of itself
 107          * under DOS since the non-binary open turns newlines into '\n'.
 108          */
 109         if(ucs == '\r'){
 110             if((ucs = read_a_wide_char(g_pico_fio.fp, input_cs)) == CCONV_EOF || ucs == '\n')
 111               break;
 112
 113             if(i < nbuf-2)              /* Bare CR. Insert it and go on... */
 114               buf[i++] = '\r';          /* else, we're up a creek */
 115         }
 116
 117         if(i >= nbuf-2){
 118             buf[nbuf - 2] = ucs;        /* store last char read */
 119             buf[nbuf - 1] = '\0';       /* and terminate it */
 120             if(charsreturned)
 121               *charsreturned = nbuf - 1;
 122
 123             if(msg && displayed == 0){
 124               emlwrite("File has long line", NULL);
 125               displayed = 1;
 126             }
 127
 128             return FIOLNG;
 129         }
 130
 131         buf[i++] = ucs;
 132     }
 133
 134     if(ucs == CCONV_EOF){
 135         if(ferror(g_pico_fio.fp)){
 136             emlwrite("File read error", NULL);
 137             if(charsreturned)
 138               *charsreturned = i;
 139
 140             return FIOERR;
 141         }
 142
 143         if(i != 0)
 144           emlwrite("File doesn't end with newline.  Adding one.", NULL);
 145         else{
 146             if(charsreturned)
 147               *charsreturned = i;
 148             return FIOEOF;
 149         }
 150     }
 151
 152     buf[i] = '\0';
 153
 154     if(charsreturned)
 155       *charsreturned = i;
 156
 157     return FIOSUC;
 158 }