c - 前一个数组追加到当前数组

Question

前一个数组附加到我想要的数组。我如何获得数组的第一部分？ (输出的第一部分)。

int main(void) {
FILE *fIn, *csis;
if (fopen_s(&csis,"csis.txt","w") != 0) {
    printf("Failed to open csis.txt for writing.\n");
}
if (fopen_s(&fIn,"congress.txt","r") != 0) {
    printf("Failed to open congress.txt for reading.\n");
}
else {
char processTxt[500] , txtUpperCase[500] ;              

    processFile(fIn, processTxt, txtUpperCase);
    printf(txtUpperCase);
    fprintf(csis,"%s",txtUpperCase);

    cipher(txtUpperCase, 13);

    /*outputCode(txtUpperCase);*/

    fclose(fIn);
    fclose(csis);

}
return 0;
}

void processFile(FILE *fIn, char *processTxt, char *txtUpperCase) {
int i = 0, j = 0;



fgets(processTxt, g_size, fIn);

for (i = 0; i < g_size; i++) {
    if (processTxt[i] == '\0')
        break;

    processTxt[i] = toUpper(processTxt[i]);                                             
}
processTxt[i] = '\0';
for (i = 0; i < g_size; i++) {
    if (processTxt[i] == '\0')
        break;

    if (isUpperCase(processTxt[i])) {               
        txtUpperCase[j] = processTxt[i];
        ++j;
    }
}
char isLowerCase(char input) {
return (input>= 'a' && input <= 'z');
}

char isUpperCase(char input) {
return (input>= 'A' && input <= 'Z');
}

char toUpper(char input) {
char upperCase = input;

if (isLowerCase(input))
    upperCase = (char)((int)input - 32);

return upperCase;
}

输出:CONGRESSSHALLMAKENOLAWRESPECTINGANESTABLISHMENTOFRELIGIONORPROHIBITINGTHEFREEEXERCISETHERE FORABRIDGINGTHEFREEDOMOFSPEECHOROFTHEPRESSORTHERIGHTOFTHEPEOPLEPEACEABLYTOASSEMBLEANDTOPETITIONTHEGOVERNMENTFORAREDRESSOFGRIEVANCESÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌCONGRESS SHALL MAKE NO LAW RESPECTING AN ESTABLISHMENT OF RELIGION, OR PROHIBITING THE FREE EXERCISE THEREOF;或剥夺言论自由或新闻自由；或人民和平集会的权利，以及向政府提出申诉的权利。

Answer 1

您似乎在 txtUpperCase 中缺少终止空字符。您的程序的具体行为未定义； fprintf 将打印它在内存中找到的任何内容，直到到达空字符，甚至超出数组末尾。这些数组似乎在您平台的内存中并排放置，因此它们都被打印出来了。