好吧，你的程序（两个）都有错误：
/* you should include <stdio.h> so fgets() can return a char *,
* If you don't, it's assumed fgets() returns an int value. */
#include <stdio.h>
main()
{
char szInLine[999];
memset(szInLine, 0, sizeof(szInLine)); /* you don't need this */
fprintf(stdout, "\nPlease enter the encrypted value:\n");
/* fgets accepts a buffer and its size, it will reserve space for
* one '\0' char. */
if (fgets(szInLine, sizeof szInLine, stdin) == NULL) {
/* it is good to print some diagnostic if you receive EOF */
return(1);
}
fprintf(stdout, "Encrypted data string contains %i characters: %s\n",
strlen(szInLine), szInLine);
/* you should return 0, here */
return(0);
}
第二个更糟糕：
/* unbalanced parenthesis, you lack a parenthesis after 'while' keyword */
while(ch = getc(stdin)) != EOF)
{
if((*szInLine++ = ch) == '\n')
{
break;
}
}
*szInLine = '\0';
/* if you move the pointer 'szInLine' it will always be pointing to the end of
* the string, so this printf will show 0 characters and an empty string, you
* had better to save the pointer at the beginning, so you don't lose the
* reference to the string beginning.
*/
fprintf(stdout, "Encrypted data string contains %i characters: %s\n", strlen(szInLine), szInLine);
这应该可行：
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
char buffer_in[1000];
char buffer_out[1000];
while (fgets(buffer_in, sizeof buffer, stdin)) {
/* you'll get a line of up to 'sizeof buffer_in - 1' chars with an
* ending '\n' (or a truncated if the line has more than 'sizeof
* buffer_in - 1' chars. Also, you'll have a '\n' at the end of the
* buffer, if the line filled partially the buffer. */
fprintf(stderr,
"String read (%d chars): %s", /* this is why I don't put a '\n' here */
strlen(buffer_in),
buffer_in);
/* encrypt(buffer_in, sizeof buffer_in, buffer_out, sizeof buffer_out); */
}
/* here you got EOF */
return 0;
}
或者如果你想使用getc():
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
/* it is very important that c be an int, see manual
* page of fgetc(), getch() or getchar() */
int c;
char buffer[1000], *p = buffer;
/* we check for buffer length and for EOF. As we are doing the hard
* work ourselves, we have to check for 'sizeof buffer - 1' to allow
* space for the '\0'. */
while ((p < buffer + sizeof buffer - 1) && ((c = getchar()) != EOF)) {
if (c == '\n') { /* A NEWLINE, act on buffer, and skip it. */
*p = '\0'; /* end the string */
printf("Read %d chars: %s\n", p - buffer, buffer);
/* crypt it ... */
/* ... */
p = buffer; /* reset buffer */
continue;
}
*p++ = c; /* add the character to the buffer */
}
/* here you got EOF */
return 0;
}
最后一点：
不要贴sn-ps的代码，而是完整的例子，因为很难确定哪些错误是在这里复制代码的错误，或者哪些是你在原始程序中犯的错误。