src/tools/data_to_source.cpp

   1 /*
   2  * Copyright 2007, Ingo Weinhold <bonefish@cs.tu-berlin.de>.
   3  * All rights reserved. Distributed under the terms of the MIT License.
   4  */
   5
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <sys/stat.h>
  12 #include <unistd.h>
  13
  14
  15 void
  16 write_string(int fd, const char* data)
  17 {
  18         int len = strlen(data);
  19         if (len == 0)
  20                 return;
  21
  22         ssize_t written = write(fd, data, len);
  23         if (written < 0) {
  24                 fprintf(stderr, "Error: Failed to write to output file: %s\n",
  25                         strerror(errno));
  26                 exit(1);
  27         }
  28 }
  29
  30
  31 int
  32 main(int argc, const char* const* argv)
  33 {
  34         if (argc != 5) {
  35                 fprintf(stderr,
  36                         "Usage: %s <data var name> <size var name> <input> <output>\n",
  37                         argv[0]);
  38                 exit(1);
  39         }
  40         const char* dataVarName = argv[1];
  41         const char* sizeVarName = argv[2];
  42         const char* inFileName = argv[3];
  43         const char* outFileName = argv[4];
  44
  45         // open files
  46         int inFD = open(inFileName, O_RDONLY);
  47         if (inFD < 0) {
  48                 fprintf(stderr, "Error: Failed to open input file \"%s\": %s\n",
  49                         inFileName, strerror(errno));
  50                 exit(1);
  51         }
  52
  53         int outFD = open(outFileName, O_WRONLY | O_CREAT | O_TRUNC,
  54                 S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
  55         if (outFD < 0) {
  56                 fprintf(stderr, "Error: Failed to open output file \"%s\": %s\n",
  57                         outFileName, strerror(errno));
  58                 exit(1);
  59         }
  60
  61         const int kCharsPerLine = 15;
  62         const int kBufferSize = 16 * 1024;
  63         unsigned char buffer[kBufferSize];
  64         char lineBuffer[128];
  65
  66         sprintf(lineBuffer, "#include <stddef.h>\n");
  67         write_string(outFD, lineBuffer);
  68         sprintf(lineBuffer, "const unsigned char %s[] = {\n", dataVarName);
  69         write_string(outFD, lineBuffer);
  70
  71         off_t offset = 0;
  72         char* lineBufferEnd = lineBuffer;
  73         *lineBufferEnd = '\0';
  74         while (true) {
  75                 // read a buffer
  76                 ssize_t bytesRead = read(inFD, buffer, kBufferSize);
  77                 if (bytesRead < 0) {
  78                         fprintf(stderr, "Error: Failed to read from input file: %s\n",
  79                                 strerror(errno));
  80                         exit(1);
  81                 }
  82                 if (bytesRead == 0)
  83                         break;
  84
  85                 // write lines
  86                 for (int i = 0; i < bytesRead; i++, offset++) {
  87                         if (offset % kCharsPerLine == 0) {
  88                                 if (offset > 0) {
  89                                         // line is full -- flush it
  90                                         strcpy(lineBufferEnd, ",\n");
  91                                         write_string(outFD, lineBuffer);
  92                                         lineBufferEnd = lineBuffer;
  93                                         *lineBufferEnd = '\0';
  94                                 }
  95
  96                                 sprintf(lineBufferEnd, "\t%u", (unsigned)buffer[i]);
  97                         } else
  98                                 sprintf(lineBufferEnd, ", %u", (unsigned)buffer[i]);
  99
 100                         lineBufferEnd += strlen(lineBufferEnd);
 101                 }
 102         }
 103
 104         // flush the line buffer
 105         if (lineBufferEnd != lineBuffer) {
 106                 strcpy(lineBufferEnd, ",\n");
 107                 write_string(outFD, lineBuffer);
 108         }
 109
 110         // close the braces and write the size variable
 111         sprintf(lineBuffer, "};\nconst size_t %s = sizeof(%s);\n", sizeVarName,
 112                 dataVarName);
 113         write_string(outFD, lineBuffer);
 114
 115         close(inFD);
 116         close(outFD);
 117
 118         return 0;
 119 }