第14课。

14/Exercise01.c

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdbool.h>
+#define MALE false
+#define FEMALE true
+
+typedef struct {
+    int year;
+    int month;
+    int date;
+} DATE;
+
+typedef struct {
+    int ID;
+    char name[21];
+    bool sex;
+    DATE birthday;
+    double score;
+} STUDENT;
+
+void saveStu(STUDENT students[], int count) {
+    int i;
+    FILE* fileObj;
+    for (i = 0; i < count; i++) {
+        printf("ID: ");
+        scanf("%d", &students[i].ID);
+        printf("Name(max 20 char): ");
+        scanf("%20s", students[i].name);
+        printf("Sex: (MALE-0/FEMLE-1)");
+        scanf("%d", &students[i].sex);
+        printf("Birthday (Year/Month/Date):");
+        scanf("%d/%d/%d", &students[i].birthday.year, &students[i].birthday.month, &students[i].birthday.date);
+        printf("Scores:\n");
+        scanf("%lf", &students[i].score);   
+    }
+    fileObj = fopen("studentInfos", "wb");
+    if (fileObj == NULL) {
+        printf("Cannot open file.\n");
+        return;
+    }
+    if (fwrite(students, sizeof(STUDENT), count, fileObj) == 0) {
+        printf("Print file error.\n");
+    }
+    fclose(fileObj);
+}
+
+void loadStu(STUDENT students[], int count) {
+    int i;
+    FILE* fileObj;
+    int targetID;
+    fileObj = fopen("studentInfos", "rb");
+    if (fileObj == NULL) {
+        printf("Cannot open file.\n");
+        return;
+    }
+    if (fread(students, sizeof(STUDENT), count, fileObj) == 0) {
+        printf("Read error.\n");
+        return;
+    }
+    fclose(fileObj);
+    printf("Loaded.\n");
+    printf("ID to be checked: ");
+    scanf("%d", &targetID);
+    for (i = 0; i < count; i++) {
+        if (targetID == students[i].ID) {
+            printf("ID:%d; Name: %s; Sex:%s; Birthday:%d/%d/%d; Score:%lf\n", students[i].ID, students[i].name, students[i].sex?"FEMALE":"MALE", students[i].birthday.year, students[i].birthday.month, students[i].birthday.date, students[i].score);
+            return;
+        }
+        
+    }
+}
+
+int main() {
+    STUDENT students[10];
+    int i = 0;
+    int count = 3;
+    char mode;
+    // freopen("fakedata","r",stdin);
+    printf("Select: (S)ave/(L)oad ");
+    scanf("%c", &mode);
+    if (mode == 's' || mode == 'S') {
+        saveStu(students, count);
+    }
+    else if (mode == 'l' || mode == 'L') {
+        loadStu(students, count);
+    }
+    
+    return 0;
+}

14/Exercise02.c

@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+char toUpper(char input) {
+    if (input >= 'a') {
+        return input - 'a' + 'A';
+    }
+    else {
+        return input;
+    }
+}
+
+int main() {
+    char ch;
+    FILE* fl;
+    fl = fopen("upper.txt", "w+");
+    while (1) {
+        ch = getchar();
+        if (ch == '#') {
+            break;
+        } 
+        fprintf(fl, "%c", toUpper(ch));
+    }
+    fflush(fl);
+    // fclose(fl);
+    // fl = fopen("upper.txt", "r");
+    rewind(fl);
+    while(!feof(fl)) {
+        putchar(fgetc(fl));
+    }
+    return 0;
+}

14/Exercise03.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char** argv) {
+    char filename[81];
+    FILE* fl;
+    char string[81];
+
+    if (argc < 2) {
+        printf("Insufficient argument\n");
+        return 0;
+    }
+    else if (argc > 2) {
+        printf("Too many arguemtns\n");
+        return 0;
+    }
+
+    
+
+    strncpy(filename, argv[1], 80);
+    
+    fl = fopen(filename, "r");
+
+    if (fl == NULL) {
+        printf("Failed to open file.\n");
+        return 0;
+    }
+
+    fscanf(fl, "%80s", string);
+
+    fclose(fl);
+    printf("Content: %s\nStringLength: %d", string, strlen(string));
+
+    return 0;
+}

14/fakedata

@@ -0,0 +1,60 @@
+s
+345
+aaa
+0
+2020/3/4
+3.5
+
+465
+bbb
+1
+2020/3/5
+4.5
+
+933
+ddd
+0
+2020/4/6
+5
+
+9688
+dadg
+0
+2020/12/6
+6.8
+
+33
+adfidadff
+0
+2020/4/6
+7.9
+
+34555
+aaa4wt
+0
+2020/3/4
+2.5
+
+463
+bbberr
+1
+2020/3/5
+6.5
+
+93364
+dddade
+0
+2020/4/6
+8
+
+9688243
+dadgjj
+0
+2020/12/6
+10
+
+33345
+adfidafd
+0
+2020/4/6
+9

14/upper.txt

@@ -0,0 +1 @@
+ADEIKKDKEI

test.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+int a = 4;
+
+int main() {
+    int s = a, i = 0;
+    printf("%d\n", s);
+    for (;i < 2; i++) {
+        s += f(i);
+    }
+    printf("%d\n%d\n%d", s, f(0), f(1));
+    return 0;
+}
+
+// printf 从右往左压栈
+// (..., ..., ...)括号里的叫逗号表达式，优先级比赋值还低
+// 挨个运算所有的表达式，整个逗号表达式的值是最后一个语句的值
+// (*p)[5] 5个指针的数组 *p[5]一个行长为5的行指针