编写服务器/客户端程序并使用Netbeans在构建时收到这些错误：
dbserver.c:195: warning: embedded '\0' in format
dbserver.c:211: warning: passing argument 1 of 'db_lookup' from incompatible pointer type
dbserver.c:213: warning: passing argument 1 of 'db_insert' from incompatible pointer type
dbserver.c:241: warning: passing argument 1 of 'db_delete' from incompatible pointer type
dbserver.c:257: warning: passing argument 1 of 'db_lookup' from incompatible pointer type
dbserver.c:287: warning: embedded '\0' in format
以下是相关代码：
//------------------------------------------------------------------------------
// Static Definitions
//------------------------------------------------------------------------------
#define WORD_LENGTH 32 //size of transmission & word length (31 characters + \0)
#define DICTIONARY_SIZE 100 //size of dictionary word count
//------------------------------------------------------------------------------
// Message Structure Definition
//------------------------------------------------------------------------------
typedef struct message
{
int msg_type; //message code used to call database functions
int msg_size; //expected size of message in transit
char msg[32]; //payload capacity
} message;
//------------------------------------------------------------------------------
// Server Function & Variable Initialization
//------------------------------------------------------------------------------
char dictionary[DICTIONARY_SIZE][WORD_LENGTH]; //dictionary structure
int word_count = 0; //dictionary word counter
int db_initialization(); //create db dictionary
int db_insert(const char *word); //check for word, insert if not found
int db_delete(const char *word); //remove word from dictionary if found
int db_lookup(const char *word); //search dictionary for word
int db_function(int fd); //db function call interface
int errexit(const char *format, ...); //Khalid's error and exit
//establishes socket to listen for connections
int listen_socket_TCP(const char *service, int qlen);
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Main Function
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
int main(int argc, char *argv[])
{
char *service = "27792"; //"Magic Port" to listen on
struct sockaddr_in client_address; //IPv4 client address
unsigned int client_address_length; //IPv4 client address length
int master_socket; //TCP socket
int slave_socket; //TCP socket spawned off of Master
master_socket = listen_socket_TCP(service, WORD_LENGTH); //build database
//------------------------------------------------------------------------------
// Dictionary Code Adapted from Material provided by Khalid
//------------------------------------------------------------------------------
db_initialization(); //initialize the database
//seed the database
db_insert("hello");
db_insert("communication");
db_insert("depaul");
db_insert("cdm");
//--------------------------------------------------------------------------
// Test Database Function Operation
//--------------------------------------------------------------------------
if (db_lookup("cti"))
printf("found\n");
//end if
else
{
db_insert("cti");
printf("'cti' has been inserted\n");
} //end else
if (db_delete("cdm"))
printf("'cdm' has been successfully deleted\n");
//end if
else
printf("cannot find 'cdm'.");
//end else
//--------------------------------------------------------------------------
// Forever Loop to Listen for Connections
//--------------------------------------------------------------------------
while (1)
{
client_address_length = sizeof(client_address);
slave_socket = accept(master_socket, (struct sockaddr *)&client_address,
&client_address_length);
if (slave_socket < 0)
errexit("accept: %s\n", strerror(errno));
//end if
printf("Connecting...\n");
db_function(slave_socket);
close(slave_socket);
} //end while
}
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// END MAIN FUNCTION
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Server Function Codes:
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Execute Database Functionality
//------------------------------------------------------------------------------
int db_function(int fd)
{
int finished = 0;
char re[2];
int x = -1;
while (!finished)
{
char buf[sizeof(message)];
int cc;
struct message *sptr;
message s;
cc = recv(fd, buf, sizeof(message), 0);
printf("Received Bytes: %i\n", cc);
sptr = (struct message *) buf;
memcpy(&s, sptr,sizeof(message));
if (s.msg_size != strlen(s.msg))
{
x = -1;
sprintf(re,"%d \0", x);
send(fd, re, 2, 0);
break;
} //end if
//----------------------------------------------------------------------
// Message Code 1 - Insert Word into Dictionary
//
// Return 1: Successfully Inserted Word
// Return 0: Word Exists in Dictionary Already
// Return -1: Failed to Add Word to Dictionary
//----------------------------------------------------------------------
if (s.msg_type == 1)
{
if ((db_lookup(&s.msg)) == 0) //search for preexisting word
{
if ((db_insert(&s.msg)) > 0) //insert word into dictionary
{
x = 1; //word added successfully
} //end insert if
else
x = -1;//unsuccessful in adding word
} //end search and insert if
else
x = 0;
printf("Adding to dictionary: %s result %i\n", s.msg, x);
} //end if message type 1
//----------------------------------------------------------------------
// Message Code 2 - Delete Word from Dictionary
//
// Return 1: Successfully Deleted Word
// Return 0: Word does not Exist in Dictionary
// Return -1: Failed to Delete Word from Dictionary
//----------------------------------------------------------------------
if (s.msg_type == 2)
{
x = db_delete(&s.msg);
printf("Deleting from dictionary: %s result %i\n", s.msg, x);
} //end if message type 2
//----------------------------------------------------------------------
// Message Code 3 - Lookup Word in Dictionary
//
// Return 1: Successfully Found Word
// Return 0: Word not FOund in Dictionary
// Return -1: Function Failed
//----------------------------------------------------------------------
if (s.msg_type == 3)
{
x = db_lookup(&s.msg);
printf("Looking up from dictionary: %s result %i\n", s.msg, x);
} //end if message type 3
//----------------------------------------------------------------------
// Message Code 4 - Close Connection
//----------------------------------------------------------------------
if (s.msg_type == 4)
{
x = 1;
printf("Closing connection: %s result %i\n", s.msg, x);
break;
} //end if message type 4
printf("Words in dictionary: {");
int c = 0;
for (c=0; c < word_count; c++)
{
printf("%s, ", dictionary[c]);
}
printf("}\n");
sprintf(re,"%d\0", x);
send(fd, re, 2, 0);
} // end while(!finished)
return 0;
} //end db_function
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Database Initialization
//------------------------------------------------------------------------------
int db_initialization()
{
word_count = 0;
return 1;
} //end db_initialization
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Insert Word into Dictionary
//------------------------------------------------------------------------------
int db_insert(const char *word)
{
strcpy(dictionary[word_count], word);
word_count++;
return word_count;
} //end db_insert
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Delete Word from Dictionary
//------------------------------------------------------------------------------
int db_delete(const char *word)
{
int i;
for (i=0 ; i < word_count ; i++)
{
if (strcmp(word, dictionary[i]) == 0)
{
word_count--;
strcpy(dictionary[i], dictionary[word_count]);
return 1;
} //end if
} //end for
return 0;
} //end db_delete
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Lookup Word in Dictionary
//------------------------------------------------------------------------------
int db_lookup(const char *word)
{
int i;
for (i=0 ; i<word_count ; i++)
{
if (strcmp(word, dictionary[i]) == 0)
return 1;
} //end for
return 0;
} //end db_lookup
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
我已经排除了预处理程序指令和listen_socket_TCP函数（在另一个源文件中）。
答案 0 :(得分：1)
首先，这些是警告，而不是错误......
无论如何，看起来问题在于你如何传递字符串：
dbserver.c:211: warning: passing argument 1 of 'db_lookup' from incompatible pointer type
db_lookup()正在寻找const char *，例如在这里使用它时：
if (db_lookup("cti"))
你传递了它：
if ((db_lookup(&s.msg)) == 0) //search for preexisting word
结构中char指针的地址，如果你只是传递它：
if ((db_lookup(s.msg)) == 0) //search for preexisting word
应该修复那种警告。
其次，从您的sprintf中删除\0以删除有关以下内容的两个警告：
warning: embedded '\0' in format