嵌入式C语言笔记：C语言标准库大全

int printf(const char *format, ...);

printf("Hello, %s!\n", "world");

int scanf(const char *format, ...);

int age;scanf("%d", &age);

int fprintf(FILE *stream, const char *format, ...);

int fscanf(FILE *stream, const char *format, ...);

FILE *fopen(const char *filename, const char *mode);

FILE *file = fopen("example.txt", "r");

int fclose(FILE *stream);

char *fgets(char *s, int size, FILE *stream);

int fputs(const char *s, FILE *stream);

int fgetc(FILE *stream);

int fputc(int c, FILE *stream);

void rewind(FILE *stream);

int feof(FILE *stream);

void *malloc(size_t size);

int *arr = (int *)malloc(5 * sizeof(int));

void *calloc(size_t num_elements, size_t element_size);

int *arr = (int *)calloc(5, sizeof(int));

void *realloc(void *ptr, size_t size);

arr = (int *)realloc(arr, 10 * sizeof(int));

void free(void *ptr);

free(arr);

int rand(void);

int random_number = rand();

void srand(unsigned int seed);

srand(42);

int abs(int n);

int absolute_value = abs(-5);

int atoi(const char *str);

int number = atoi("42");

double atof(const char *str);

double pi = atof("3.14159");

void exit(int status);

exit(0); // 正常退出

int system(const char *command);

system("ls -l");

void qsort(void *base, size_t num_elements, size_t element_size, int (*compare_function)(const void *, const void *));

int compare(const void *a, const void *b) {return (*(int *)a - *(int *)b);}

int arr[] = {5, 2, 9, 1, 5};qsort(arr, 5, sizeof(int), compare);

char *strcpy(char *dest, const char *src);

char destination[20];char source[] = "Hello, world!";strcpy(destination, source);

char *strcat(char *dest, const char *src);

char str1[20] = "Hello, ";char str2[] = "world!";strcat(str1, str2);

size_t strlen(const char *s);

char str[] = "Hello";size_t length = strlen(str);

int strcmp(const char *s1, const char *s2);

char str1[] = "apple";char str2[] = "banana";int result = strcmp(str1, str2);

int strncmp(const char *s1, const char *s2, size_t n);

char str1[] = "apple";char str2[] = "appetizer";int result = strncmp(str1, str2, 3);

char *strchr(const char *s, int c);

char str[] = "Hello, world!";char *result = strchr(str, 'w');

char *strstr(const char *haystack, const char *needle);

char str[] = "The quick brown fox";char *result = strstr(str, "brown");

char *strtok(char *str, const char *delimiters);

char str[] = "apple,banana,grape";char *token = strtok(str, ",");while (token != NULL) {printf("%s\n", token);token = strtok(NULL, ",");}