dump.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 88 行

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main(int argc, char* argv[])
{
  FILE *fi; /* Stream pointer of file to dump.*/
  int aux; /* Integer representation of the last character read.*/
  long start_pos; /* Position of the first byte to write to stdout.*/
  long end_pos; /* Position of last byte to write to stdout.*/
  long file_size; /* Size in bytes of the input file.*/
  int change_endian = 0;  /* 0 leaves original byte order intact, 1 changes endian.*/
  
  /* Determine if the byte order needs to be changed.*/
  if (argc > 2 && strcmp(argv[2], "-ch32") == 0) change_endian = 1;

  switch (argc-change_endian) {
  case 2: /* Dump whole file */
    start_pos = 0;
    end_pos = -1;
    break;
  case 3: /* Dump from postion argv[2] till end of file*/
    start_pos = atol(argv[2+change_endian]);
    end_pos = -1;
    break;
  case 4: /* Dump from argv[2] till argv[3] */
  case 5: /* Dump from argv[2] till argv[3] */
    start_pos = atol(argv[2+change_endian]);
    end_pos = atol(argv[3+change_endian]);
    break;
  default:
    if (argc != 1) fprintf(stderr, "ERROR! Invalid usage!\n\n");
    fprintf(stderr, "Description: dump echoes a portion of a file to stdout.\n");
    fprintf(stderr, "Syntax: dump filename [options] [first_byte_pos [last_byte_pos [fill_char]]]\n");
    fprintf(stderr, "  options        : -ch32 changes byte order little<->big endian\n");
    fprintf(stderr, "  options        :       for 4-byte blocks.\n");
    fprintf(stderr, "  first_byte_pos : file_size_in_bytes-1 is allowed.\n");
    fprintf(stderr, "  last_byte_pos  : file_size_in_bytes-1 if absent\n");
    fprintf(stderr, "  fill_char      : character that should fill the gap between\n");
    fprintf(stderr, "                   last_byte_pos and file_size_in_bytes-1\n");
    fprintf(stderr, "                   Escape character (\\) + number allowed\n");
    fprintf(stderr, "                   e.g.: For '\\n' use '\\10'\n");
    exit(0);
  };

  /* Verify that the file exists.*/
  fi = fopen(argv[1],"rb");
  if (fi == NULL) {
    fprintf(stderr, "ERROR! Could not open input file %s.\n", argv[1]);
    exit(0);
  };
  
  /* Set end_pos and file_size.*/
  fseek(fi, 0L, SEEK_END); file_size = ftell(fi);
  if (end_pos == -1) end_pos = file_size - 1;
  
  /* Verify that begin_pos and end_pos are valid and correct if possible.*/
  if (start_pos>end_pos) return 0; /* Nothing to do.*/
  if (start_pos<0 || end_pos<0) return 0; /* Not allowed.*/

  /* Dump part of the file if necessary.*/
  if (start_pos<file_size) {
    /* Part of the file needs to be dumped. So do it.*/
    fseek(fi, start_pos, SEEK_SET);
    while (ftell(fi) <= end_pos) {
      aux = fgetc(fi);
      if (aux == EOF) break;
      fputc(aux, stdout);
    };
  };

  /* Check if we need to dump filler bytes.*/
  if (argc-change_endian == 5 && end_pos>file_size-1) {
    /* The user has defined a filler byte and there are bytes*/
    /* to be filled. Determine how many.*/
    long fill_count; /* Number of bytes to fill.*/
    int filler; /* Character to use as a filler.*/
    fill_count = (start_pos<file_size? end_pos-file_size+1: end_pos-start_pos+1);
    if (*argv[4+change_endian] == '\\')
      filler = atoi(argv[4]+1);
    else
      filler = (int)*argv[4+change_endian];
    while (fill_count-- > 0)
        fprintf(stdout, "%c", filler);
  };
  return 0;
}