如果每一行被换行终止，则读取C中的文件

Apparently I'm having some issue reading a file, line by line, or character by character, because each row of my file is terminated by a newline character. I think the issue is related to those newline characters because when I'm trying to read the file, using or fgetc() or fgets(), when I attempt to print the result on stdout I'm given... nothing.

显然，我对逐行读取文件或逐行读取字符有一些问题，因为文件的每一行都以换行符结束。我认为这个问题与这些换行字符有关，因为当我尝试读取文件时，使用或fgetc()或fgets()，当我尝试在stdout上打印结果时，我得到了……什么都没有。

Example of first file that gives me the issue:

给我的第一个文件的例子:

12345678
12849499
47484900

I tried with another file, such as

我尝试了另一个文件，比如。

123456596945869498

And the output on stdout, parsing the file using fgetc() or fgets(), is what I expect: the content of the file.

而stdout的输出，使用fgetc()或fgets()解析文件，是我所期望的:文件的内容。

Now, the aim of the read from file is to store the content of the file in a matrix at pointers. I tried in many ways to bypass those newlines. I tried like this:

现在，从文件读取的目的是将文件的内容存储在一个指针上的矩阵中。我尝试了很多方法来绕过这些新思路。我试着像这样:

i = 0;
while((c = fgetc(f)) != EOF){
    if(c != '\n')
       p[i][j++] = c; /*Incrementing j by one ad each iteration */
    if(c == '\n')
        i++; /*If c == '\n', skip to the next row of the matrix */
    }

Where I is the row index and j is the column index. I even tried with fgets, like this, as suggested by a member of this forum:

其中I是行索引，j是列索引。我甚至尝试过fgets，就像这个论坛的一位成员建议的那样:

while((fgets(line, col,f))!= NULL){
        p[i++] = strdup(line);
        }

Can anybody help me figuring out how to solve this issue?

谁能帮我解决这个问题吗?

This is the main of the my program:

这是我项目的主要内容:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define K 100

int main() {
  FILE *f;

  f = fopen("out_test6_1.txt", "r");

  int row = 0;
  int col = 0;
  char c;

  // Evaluating number of rows and columns of the new matrix, 
  // parsing the file in search of newlines chars

  while((c = fgetc(f)) != EOF ) {
    if(c != '\n' && row == 0)
    col++;

    else if(c == '\n')
    row++;
  }

  printf("rows %d\n", row);
  printf("columns %d\n", col);

  int i, j;
  char**p = malloc(row*sizeof(char*));
  for(i = 0; i < row; i++) {
    p[i] = malloc(col*sizeof(char));
  }

  i = 0;
  while((c = fgetc(f)) != EOF) {
    if(c != '\n')
    p[i][j++] = c;
    if(c == '\n')
    i++;
  }

  for(i = 0; i < row; i++) {
    for(j = 0; j < col; j++) {
      printf("%c", p[i][j]);
    }
  }

  fclose(f);

  return 0;
}

1 个解决方案

#1

Code reads the file to find the rows and columns yet fails to rewind before the 2nd pass.

代码读取文件以查找行和列，但在第2遍前未能回滚。

i = 0;
rewind(f);  // add
while((c = fgetc(f)) != EOF) {

Some other problems noted:

其他一些问题指出:

// To properly distinguish all characters from EOF
// char c;
int c;

I'd expect code to find the maximum column width and use that later.

我希望代码能够找到最大的列宽度并在以后使用。

  size_t max_col = 0;
  while((c = fgetc(f)) != EOF ) {
    col++;
    if (c == '\n') {
      if (col > max_col) {
        max_col = col;
        col = 0;
      }
      row++;
    }
  }
  if (col > max_col) {
    max_col = col;
  }

  ... 
  // p[i] = malloc(col*sizeof(char));
  p[i] = malloc(sizeof *(p[i]) * max_col);

#1