C语言 逐字读取文件
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/16400886/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Reading from a file word by word
提问by Andrea Gottardi
I have a custom archive structured as follows:
我有一个自定义存档结构如下：
%list% name1 name2 name3 %list%
%dirs% archive directories %dirs%
%content% name1 path1 content of file1 %content%
%content% name2 path2 content of file2 %content%
%content% name3 path3 content of file3 %content%
%list%contains names of files in archive
%dirs%contains names of directories
%content%lists file contents.
%list%包含存档中的文件名
%dirs%包含目录名
%content%列出文件内容。
Since i need to print the content of a specified file, i want to read this archive word by word, in order to identify %content%tag and file name.
I know the existence of fscanf(), but it seems to work efficiently only if you know the archive pattern.
由于我需要打印指定文件的内容，我想逐字读取这个存档，以便识别%content%标签和文件名。
我知道 的存在fscanf()，但它似乎只有在您知道存档模式时才能有效地工作。
Is there a C library or command, like ifstreamfor C++, that allows me to read word by word?
是否有 C 库或命令，例如ifstreamC++，允许我逐字阅读？
Thanks
谢谢
回答by jxh
You can just use fscanfto read one word at a time:
你可以fscanf一次只读一个单词：
void read_words (FILE *f) {
char x[1024];
/* assumes no word exceeds length of 1023 */
while (fscanf(f, " %1023s", x) == 1) {
puts(x);
}
}
If you don't know the maximum length of each word, you can use something similar to this answerto get the complete line, then use sscanfinstead, using a buffer as large as the one created to read in the complete line. Or, you could use strtokto slice the read in line up into words.
如果您不知道每个单词的最大长度，您可以使用类似于此答案的方法来获取完整行，然后使用sscanf与创建的缓冲区一样大的缓冲区来读取完整行。或者，您可以使用strtok将读取的内容分成单词。
回答by BLUEPIXY
like this
像这样
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
typedef char Type;
typedef struct vector {
size_t size;
size_t capacity;
Type *array;
} Vector;
Vector *vec_make(){
Vector *v;
v = (Vector*)malloc(sizeof(Vector));
if(v){
v->size = 0;
v->capacity=16;
v->array=(Type*)realloc(NULL, sizeof(Type)*(v->capacity += 16));
}
return v;
}
void vec_add(Vector *v, Type value){
v->array[v->size] = value;
if(++v->size == v->capacity){
v->array=(Type*)realloc(v->array, sizeof(Type)*(v->capacity += 16));
if(!v->array){
perror("memory not enough");
exit(-1);
}
}
}
void vec_reset(Vector *v){
v->size = 0;
}
size_t vec_size(Vector *v){
return v->size;
}
Type *vec_getArray(Vector *v){
return v->array;
}
void vec_free(Vector *v){
free(v->array);
free(v);
}
char *fin(FILE *fp){
static Vector *v = NULL;
int ch;
if(v == NULL) v = vec_make();
vec_reset(v);
while(EOF!=(ch=fgetc(fp))){
if(isspace(ch)) continue;//skip space character
while(!isspace(ch)){
vec_add(v, ch);
if(EOF == (ch = fgetc(fp)))break;
}
vec_add(v, '##代码##');
break;
}
if(vec_size(v) != 0) return vec_getArray(v);
vec_free(v);
v = NULL;
return NULL;
}
int main(void){
FILE *fp = stdin;
char *wordp;
while(NULL!=(wordp=fin(fp))){
printf("%s\n", wordp);
}
return 0;
}
