Stray Error while compiling

Hello, I am still new with programming in C through Fedora terminal.

I am trying to get an early start on my lab that is on Wed. - so I copy and paste the code and I get Stray errors. I don't know id the "\" is the cause and before I start removing code from the lab, I want to know what is causing this issue. If I comment the lines out, the program while compile so I know it happens to do with those two lines. I "google" the errors and the results seem to be the inputting characters that aren't ASC. Can someone please explain this issue to happen because this is happening on more than one lab for the future. Thanks!

Code:

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define MYPORT 4950 // the port users will be connecting to
#define MAXBUFLEN 100
int main(void)
{
        int sockfd;
        struct sockaddr_in my_addr; // my address information
        struct sockaddr_in their_addr; // connector’s address information
        socklen_t addr_len;
        int numbytes;
        char buf[MAXBUFLEN];
        if ((sockfd = socket(PF_INET, SOCK_DGRAM, 0)) == -1) {
                perror("socket");
                exit(1);
        }
my_addr.sin_family = AF_INET; // host byte order
        my_addr.sin_port = htons(MYPORT); // short, network byte order
        my_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP
        memset(&(my_addr.sin_zero), ’\0’, 8); // zero the rest of the struct
        if (bind(sockfd, (struct sockaddr *)&my_addr,
                sizeof(struct sockaddr)) == -1) {
                perror("bind");
                exit(1);
        }
        addr_len = sizeof(struct sockaddr);
        if ((numbytes=recvfrom(sockfd, buf, MAXBUFLEN-1 , 0,
                (struct sockaddr *)&their_addr, &addr_len)) == -1) {
                perror("recvfrom");
                exit(1);
        }
        printf("got packet from %s\n",inet_ntoa(their_addr.sin_addr));
        printf("packet is %d bytes long\n",numbytes);
        buf[numbytes] = ’\0’;
                printf("packet contains \"%s\"\n",buf);
        close(sockfd);
        return 0;
}

---

Error Code:

Code:

---

listener.c: In function ‘main’:
listener.c:27: error: stray ‘\342’ in program
listener.c:27: error: stray ‘\200’ in program
listener.c:27: error: stray ‘\231’ in program
listener.c:27: error: stray ‘\’ in program
listener.c:27: error: stray ‘\342’ in program
listener.c:27: error: stray ‘\200’ in program
listener.c:27: error: stray ‘\231’ in program
listener.c:41: error: stray ‘\342’ in program
listener.c:41: error: stray ‘\200’ in program
listener.c:41: error: stray ‘\231’ in program
listener.c:41: error: stray ‘\’ in program
listener.c:41: error: stray ‘\342’ in program
listener.c:41: error: stray ‘\200’ in program
listener.c:41: error: stray ‘\231’ in program

---

It seems if i change ’\0’ to '\0' - it can compile. Is this correct?

from:
memset(&(my_addr.sin_zero), ’\0’, 8);
to
memset(&(my_addr.sin_zero), '\0', 8);

Yeah, it usually means you've copied code from some website, which has been munged to "look good" by using different quote characters.

indeed, you have to use a simple quote '...' to enclose a character

Thanks for the information and reason for the code error - Thanks again!

i am trying the following program and it gives some errors while compiling. i cant figure out what the error is. can someone please help me? thanks in advance.

Code:

---

#include<stdio.h>
#include<math.h>
float detrm( float[][], float );
void cofact( float[][], float );
void trans( float[][], float[][], float );
main()
{
    float a[ 25 ][ 25 ], k, d;
    int i, j;
    printf( "ENTER THE ORDER OF THE MATRIX:\n" );
    scanf( "%f", &k );
    printf( "ENTER THE ELEMENTS OF THE MATRIX:\n" );
 
    for ( i = 0;i < k;i++ )
        {
            for ( j = 0;j < k;j++ )
                {
                    scanf( "%f", &a[ i ][ j ] );
                }
        }
 
    d = detrm( a, k );
    printf( "THE DETERMINANT IS=%f", d );
 
    if ( d == 0 )
        printf( "\nMATRIX IS NOT INVERSIBLE\n" );
    else
        cofact( a, k );
}
 
/******************FUNCTION TO FIND THE DETERMINANT OF THE MATRIX************************/
 
float detrm( float a[ 25 ][ 25 ], float k )
{
    float s = 1, det = 0, b[ 25 ][ 25 ];
    int i, j, m, n, c;
 
    if ( k == 1 )
        {
            return ( a[ 0 ][ 0 ] );
        }
    else
        {
            det = 0;
 
            for ( c = 0;c < k;c++ )
                {
                    m = 0;
                    n = 0;
 
                    for ( i = 0;i < k;i++ )
                        {
                            for ( j = 0;j < k;j++ )
                                {
                                    b[ i ][ j ] = 0;
 
                                    if ( i != 0 && j != c )
                                        {
                                            b[ m ][ n ] = a[ i ][ j ];
 
                                            if ( n < ( k – 2 ) )
                                                n++;
                                            else
                                                {
                                                    n = 0;
                                                    m++;
                                                }
                                        }
                                }
                        }
 
                    det = det + s * ( a[ 0 ][ c ] * detrm( b, k – 1 ) );
                    s = -1 * s;
                }       
        }
 
    return ( det );
}
 
/*******************FUNCTION TO FIND COFACTOR*********************************/
 
void cofact( float num[ 25 ][ 25 ], float f )
{
    float b[ 25 ][ 25 ], fac[ 25 ][ 25 ];
    int p, q, m, n, i, j;
 
    for ( q = 0;q < f;q++ )
        {
            for ( p = 0;p < f;p++ )
                {
                    m = 0;
                    n = 0;
 
                    for ( i = 0;i < f;i++ )
                        {
                            for ( j = 0;j < f;j++ )
                                {
                                    b[ i ][ j ] = 0;
 
                                    if ( i != q && j != p )
                                        {
                                            b[ m ][ n ] = num[ i ][ j ];
 
                                            if ( n < ( f – 2 ) )
                                                n++;
                                            else
                                                {
                                                    n = 0;
                                                    m++;
                                                }
                                        }
                                }
                        }
 
                    fac[ q ][ p ] = pow( -1, q + p ) * detrm( b, f – 1 );
                }
        }
 
    trans( num, fac, f );
}
 
/*************FUNCTION TO FIND TRANSPOSE AND INVERSE OF A MATRIX**************************/
 
void trans( float num[ 25 ][ 25 ], float fac[ 25 ][ 25 ], float r )
 
{
    int i, j;
    float b[ 25 ][ 25 ], inv[ 25 ][ 25 ], d;
 
    for ( i = 0;i < r;i++ )
        {
            for ( j = 0;j < r;j++ )
                {
                    b[ i ][ j ] = fac[ j ][ i ];
                }
        }
 
    d = detrm( num, r );
    inv[ i ][ j ] = 0;
 
    for ( i = 0;i < r;i++ )
        {
            for ( j = 0;j < r;j++ )
                {
                    inv[ i ][ j ] = b[ i ][ j ] / d;
                }
        }
 
    printf( "\nTHE INVERSE OF THE MATRIX:\n" );
 
    for ( i = 0;i < r;i++ )
        {
            for ( j = 0;j < r;j++ )
                {
                    printf( "\t%f", inv[ i ][ j ] );
                }
 
            printf( "\n" );
        }
}

---

the errors are...


[ERROR CODE]
/home/samy/programs/inversematrix/main.cpp:61: error: stray ‘\342’ in program
/home/samy/programs/inversematrix/main.cpp:61: error: stray ‘\200’ in program
/home/samy/programs/inversematrix/main.cpp:61: error: stray ‘\223’ in program
/home/samy/programs/inversematrix/main.cpp:72: error: stray ‘\342’ in program
/home/samy/programs/inversematrix/main.cpp:72: error: stray ‘\200’ in program
/home/samy/programs/inversematrix/main.cpp:72: error: stray ‘\223’ in program
/home/samy/programs/inversematrix/main.cpp:104: error: stray ‘\342’ in program
/home/samy/programs/inversematrix/main.cpp:104: error: stray ‘\200’ in program
/home/samy/programs/inversematrix/main.cpp:104: error: stray ‘\223’ in program
/home/samy/programs/inversematrix/main.cpp:115: error: stray ‘\342’ in program
/home/samy/programs/inversematrix/main.cpp:115: error: stray ‘\200’ in program
/home/samy/programs/inversematrix/main.cpp:115: error: stray ‘\223’ in program
/home/samy/programs/inversematrix/main.cpp:3: error: multidimensional array must have bounds for all dimensions except the first
/home/samy/programs/inversematrix/main.cpp:4: error: multidimensional array must have bounds for all dimensions except the first
/home/samy/programs/inversematrix/main.cpp:5: error: multidimensional array must have bounds for all dimensions except the first
/home/samy/programs/inversematrix/main.cpp:5: error: multidimensional array must have bounds for all dimensions except the first
/home/samy/programs/inversematrix/main.cpp: In function ‘int main()’:
/home/samy/programs/inversematrix/main.cpp:22: error: cannot convert ‘float (*)[25]’ to ‘float’ for argument ‘1’ to ‘float detrm(float)’
/home/samy/programs/inversematrix/main.cpp:28: error: cannot convert ‘float (*)[25]’ to ‘float’ for argument ‘1’ to ‘void cofact(float)’
/home/samy/programs/inversematrix/main.cpp: In function ‘float detrm(float (*)[25], float)’:
/home/samy/programs/inversematrix/main.cpp:61: error: expected ‘)’ before numeric constant
/home/samy/programs/inversematrix/main.cpp:62: error: expected ‘)’ before ‘;’ token
/home/samy/programs/inversematrix/main.cpp:72: error: expected ‘)’ before numeric constant
/home/samy/programs/inversematrix/main.cpp: In function ‘void cofact(float (*)[25], float)’:
/home/samy/programs/inversematrix/main.cpp:104: error: expected ‘)’ before numeric constant
/home/samy/programs/inversematrix/main.cpp:105: error: expected ‘)’ before ‘;’ token
/home/samy/programs/inversematrix/main.cpp:115: error: expected ‘)’ before numeric constant
/home/samy/programs/inversematrix/main.cpp:119: error: cannot convert ‘float (*)[25]’ to ‘float’ for argument ‘1’ to ‘void trans(float)’[/CODE]

1. Don't pick a random irrelevant three-year-old thread to post in, but make your own.

2. When it says "multidimensional array must have bounds for all dimensions except the first", they mean it. You can't pass arbitrary-in-all-dimensions arrays around.

3. You have weird symbols on line 61, 72, 104, and 115. So use a normal symbol instead. A rough guess is that you have something like a fancy - sign instead of a normal - sign.

EDIT: In fact the three symbols listed, 0xE2, 0x80, 0x93, are the UTF-8 equivalent of the Unicode U+2013, which conveniently enough is "En Dash".