根据您在 cmets 部分提供的信息，输入文本长度超过 800 字节。
但是，在行中
char *text = malloc(sizeof(WORD_BUFFER_SIZE)*TEXT_SIZE);
相当于
char *text = malloc(800);
您只为 text 分配了 800 个字节作为存储空间。因此，您没有分配足够的空间来将整个输入存储到text。尝试存储超过 800 个字节将导致 buffer overflow，它调用 undefined behavior。
如果要将整个输入存储到text，则必须确保它足够大。
但是，这可能不是必需的。根据您的要求，一次处理一行可能就足够了，如下所示：
while( fgets( buffer, sizeof buffer, stdin ) != NULL )
{
char *k = strtok( buffer, " " );
while ( k != NULL )
{
printf( "%s\n", k );
k = strtok( NULL, " " );
}
}
在这种情况下，您不需要数组text。您只需要数组buffer 来存储该行的当前内容。
由于您没有提供任何示例输入，我无法测试上面的代码。
编辑：根据您对这个答案的 cmets，您的主要问题似乎是当您不知道输入的长度时，如何从 stdin 读取所有输入并将其存储为字符串前进。
一种常见的解决方案是分配一个初始缓冲区，并在每次填满时将其大小加倍。您可以为此使用函数realloc：
#include <stdio.h>
#include <stdlib.h>
int main( void )
{
char *buffer;
size_t buffer_size = 1024;
size_t input_size = 0;
//allocate initial buffer
buffer = malloc( buffer_size );
if ( buffer == NULL )
{
fprintf( stderr, "allocation error!\n" );
exit( EXIT_FAILURE );
}
//continuously fill the buffer with input, and
//grow buffer as necessary
for (;;) //infinite loop, equivalent to while(1)
{
//we must leave room for the terminating null character
size_t to_read = buffer_size - input_size - 1;
size_t ret;
ret = fread( buffer + input_size, 1, to_read, stdin );
input_size += ret;
if ( ret != to_read )
{
//we have finished reading from input
break;
}
//buffer was filled entirely (except for the space
//reserved for the terminating null character), so
//we must grow the buffer
{
void *temp;
buffer_size *= 2;
temp = realloc( buffer, buffer_size );
if ( temp == NULL )
{
fprintf( stderr, "allocation error!\n" );
exit( EXIT_FAILURE );
}
buffer = temp;
}
}
//make sure that `fread` did not fail end due to
//error (it should only end due to end-of-file)
if ( ferror(stdin) )
{
fprintf( stderr, "input error!\n" );
exit( EXIT_FAILURE );
}
//add terminating null character
buffer[input_size++] = '\0';
//shrink buffer to required size
{
void *temp;
temp = realloc( buffer, input_size );
if ( temp == NULL )
{
fprintf( stderr, "allocation error!\n" );
exit( EXIT_FAILURE );
}
buffer = temp;
}
//the entire contents is now stored in "buffer" as a
//string, and can be printed
printf( "contents of buffer:\n%s\n", buffer );
free( buffer );
}
上面的代码假定输入将在文件结束条件下终止，如果输入是从文件通过管道传输的，情况可能就是这种情况。
再想一想，与其在代码中为整个文件设置一个大字符串，不如在代码中使用一个 char* 数组，每个字符串代表一行，例如lines[0] 将是第一行的字符串，lines[1] 将是第二行的字符串。这样，您可以轻松地使用strstr 来查找“====”分隔符，并在每一行上使用strchr 来查找各个单词，并且仍然将所有行保留在内存中以供进一步处理。
在这种情况下，我不建议您使用strtok，因为该函数通过将分隔符替换为空字符来修改字符串，因此具有破坏性。如果您需要字符串进行进一步处理，正如您在 cmets 部分中所述，那么这可能不是您想要的。这就是为什么我建议您改用strchr。
如果在编译时已知合理的最大行数，则解决方案相当简单：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_LINE_LENGTH 1024
#define MAX_LINES 1024
int main( void )
{
char *lines[MAX_LINES];
int num_lines = 0;
char buffer[MAX_LINE_LENGTH];
//read one line per loop iteration
while ( fgets( buffer, sizeof buffer, stdin ) != NULL )
{
int line_length = strlen( buffer );
//verify that entire line was read in
if ( buffer[line_length-1] != '\n' )
{
//treat end-of file as equivalent to newline character
if ( !feof( stdin ) )
{
fprintf( stderr, "input line exceeds maximum line length!\n" );
exit( EXIT_FAILURE );
}
}
else
{
//remove newline character from string
buffer[--line_length] = '\0';
}
//allocate memory for new string and add to array
lines[num_lines] = malloc( line_length + 1 );
//verify that "malloc" succeeded
if ( lines[num_lines] == NULL )
{
fprintf( stderr, "allocation error!\n" );
exit( EXIT_FAILURE );
}
//copy line to newly allocated buffer
strcpy( lines[num_lines], buffer );
//increment counter
num_lines++;
}
//All input lines have now been successfully read in, so
//we can now do something with them.
//handle one line per loop iteration
for ( int i = 0; i < num_lines; i++ )
{
char *p, *q;
//attempt to find the " ==== " marker
p = strstr( lines[i], " ==== " );
if ( p == NULL )
{
printf( "Warning: skipping line because unable to find \" ==== \".\n" );
continue;
}
//skip the " ==== " marker
p += 6;
//split tokens on remainder of line using "strchr"
while ( ( q = strchr( p, ' ') ) != NULL )
{
printf( "found token: %.*s\n", (int)(q-p), p );
p = q + 1;
}
//output last token
printf( "found token: %s\n", p );
}
//cleanup allocated memory
for ( int i = 0; i < num_lines; i++ )
{
free( lines[i] );
}
}
使用以下输入运行上述程序时
first line before deliminator ==== first line after deliminator
second line before deliminator ==== second line after deliminator
它有以下输出：
found token: first
found token: line
found token: after
found token: deliminator
found token: second
found token: line
found token: after
found token: deliminator
但是，如果在编译时没有已知的合理最大行数，那么数组lines 也必须设计为以与前面程序中的buffer 类似的方式增长。这同样适用于最大行长度。