CODEWITHSUNDEEP
cterminal
f.kol
f.kol

Reputation: 13

Different outputs in Xcode and terminal

This code gives an output:

in Xcode console: for 2015-12-23 output date: Wed 2015-12-23

on linux terminal: for 2015-12-23 output 2015-08-26 (before 2015 it's just a space)

Can anybody tell me how it's possible? I tried puts() method when printing a date, but it didn't help too.

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <time.h>
#include <string.h>

// Functions declaration
int StringLength(char *string);
bool IsDate (char myString[100], int length);
bool IsNumber (char myString[100], int length);
bool IsPrime (char myString[100]);
bool IsPalindrome (char myString[100], int length);

// Global variables declaration
int i;
int code;

bool tmp = true;
bool date = true;

char buffer[3];

int main(int argc, const char * argv[]) {

    char unknownString[100];
    printf("Insert a date string: ");
    code = scanf("%100s", unknownString);

    while (code == 1) {

        date = IsDate(unknownString, strlen(unknownString));
        printf("date: %s %s\n", buffer, unknownString);

        printf("Insert a date string: ");
        code = scanf("%100s", unknownString);
    }

    return 0;
}

bool IsDate (char myString[100], int length) {

    tmp = true;
    struct tm timeString;

    // Only unknownString == 10 could be date because of the format DDDD-DD-DD which has 10 characters
    if (length == 10) {
        // Without this condition, IsDate would be true with format 1234x56x78
        if (myString[4] == '-' && myString[7] == '-') {

            timeString.tm_year = atoi(myString) - 1900;
            timeString.tm_mon = atoi(&myString[5]) - 1;
            timeString.tm_mday = atoi(&myString[8]);
            timeString.tm_hour = 0;
            timeString.tm_min = 0;
            timeString.tm_sec = 1;
            timeString.tm_isdst = 0;

            if (mktime(&timeString) == -1) {
                fprintf(stderr, "Unable to make time.\nError in IsDate function.\n");
                exit(1);
            }
            else {
                strftime(buffer, sizeof(buffer), "%c", &timeString);
            }
        }
        else {
            tmp = false;
        }
    }
    // If length is different than 10
    else {
        tmp = false;
    }

    return tmp;
}

Upvotes: 1

Views: 96

Answers (1)

chqrlie
chqrlie

Reputation: 144520

Buffer buffer is too short for a locale’s appropriate date and time representation. Make this buffer at least 32 bytes.

char buffer[32];

I believe you found a bug in Xcode, this code:

strftime(buffer, sizeof(buffer), "%c", &timeString);

Should never produce Wed in buffer. It should either produce nothing as it does in terminal or clip the name to 2 characters We. If you are only interested in the weekday abbreviation, make the buffer at least 4 bytes and use format "%a".

Upvotes: 1

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