Thread: Display return value from a function

I want to print a return value of 1 or 0 or some other number in a c program to the screen.

Code:

  if ( readFile() != 0 )
        {
   
                fprintf(stderr, "Unable to read input file!\n");
                program_exit(E_FILES_READ);
        }
      printf("equals zero \n");

int readFile()
{
        char revAccName[51];
        char custSortCode[7];
        char custAccNum[9];
        char custAccName[19];
        char amount[12];
        char date[9];
        char id1[21];
        char id2[21];
        char id3[21];
        char reason[2];
        char record[292];
        cur = &head;
        for(;;)
        {
                if ( !fgets(record, 291, inFile) )
                        break;
                if (strlen(record) < 101)
                        return 1;
                strncpy(revAccName, &record[5], 50);
                revAccName[50] = 0;
                strncpy(custSortCode, &record[55], 6);
                custSortCode[6] = 0;
                strncpy(custAccNum, &record[61], 8);
                custAccNum[8] = 0;
                strncpy(custAccName, &record[69], 18);
                custAccName[18] = 0;
                strncpy(amount, &record[87], 11);
                amount[11] = 0;
                strncpy(id1, &record[106], 20);
                id1[20] = 0;
                strncpy(id2, &record[126], 20);
                id2[20] = 0;
                strncpy(id3, &record[146], 20);
                id3[20] = 0;
                strncpy(reason, &record[166], 1);
                reason[1] = 0;

                /* Allocate space for the record and hook it up to list. */
                *cur = (unpaids_t *)calloc(1, sizeof(unpaids_t));
                if (!*cur)
                        return 1;
                strcpy((*cur)->revAccName, &revAccName[strspn(revAccName," ")]);
                strcpy((*cur)->custSortCode, &custSortCode[strspn(custSortCode," ")]);
                strcpy((*cur)->custAccNum, &custAccNum[strspn(custAccNum," ")]);
                strcpy((*cur)->custAccName, &custAccName[strspn(custAccName," ")]);
                strcpy((*cur)->amount, &amount[strspn(amount," ")]);
                strcpy((*cur)->id1, &id1[strspn(id1," ")]);
                strcpy((*cur)->id2, &id2[strspn(id2," ")]);
                strcpy((*cur)->id3, &id3[strspn(id3," ")]);
                strcpy((*cur)->reason, &reason[strspn(reason," ")]);
                (*cur)->next = NULL;
                cur = &((*cur)->next);
        }
}

The program originally worked like this.

Since moving to a new unix box it fails. Do we think the version of the OS needs to explicitly have a return 0;

It's not my code it's someone elses and I am loathe to change anything because it has always worked before.

Sun 5.9 original

SunOS 5.10 now.

Adding in the return 0 fixes it. But the program does work on 5.9

I would also maybe like to print the return code any suggestions ?

you need a return statement at the bottom of your function. It may seem to work on some systems because you are unlucky, but the return value will be undefined if there is not explicit return statement.

Originally Posted by mapleleafblue

Since moving to a new unix box it fails. Do we think the version of the OS needs to explicitly have a return 0;

It's not my code it's someone elses and I am loathe to change anything because it has always worked before.

Sun 5.9 original

SunOS 5.10 now.

Adding in the return 0 fixes it. But the program does work on 5.9

I would also maybe like to print the return code any suggestions ?

It's not the OS but the compiler version that needs to be looked at. If a function doesn't have an explicit return, the compiler will put one in for you. A free return statement is supplied at the end of each function definition, so running off the end causes control, but no value, to be returned to the caller. The OS has nothing to do with it so your best bet is to insert a return statement and not leave anything to chance or the compiler .

Here's something you can try. Compile the source on 5.9 and move the executable to the 5.10 box and run it there to see if that makes a difference. If backwards compatibility is preserved in the compiler versions, this should work and pinpoint the cause.

You do in fact have return values for your function:

Code:

...

if (strlen(record) < 101)
                        return 1;
...

if (!*cur)
                        return 1;

The problem here is that either one of those will have to be successful in order to satisfy the return value of the function call. From the use of your for(; you better!