函數名: setvisualpage
功能: 設置可見圖形頁號
用法: void far setvisualpage(int pagenum);
程序例:
#include
#include
#include
#include
int main(void)
{
/* select a driver and mode that supports */
/* multiple pages. */
int gdriver = EGA, gmode = EGAHI, errorcode;
int x, y, ht;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
x = getmaxx() / 2;
y = getmaxy() / 2;
ht = textheight("W");
/* select the off screen page for drawing */
setactivepage(1);
/* draw a line on page #1 */
line(0, 0, getmaxx(), getmaxy());
/* output a message on page #1 */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "This is page #1:");
outtextxy(x, y+ht, "Press any key to halt:");
/* select drawing to page #0 */
setactivepage(0);
/* output a message on page #0 */
outtextxy(x, y, "This is page #0.");
outtextxy(x, y+ht, "Press any key to view page #1:");
getch();
/* select page #1 as the visible page */
setvisualpage(1);
/* clean up */
getch();
closegraph();
return 0;
}
函數名: setwritemode
功能: 設置圖形方式下畫線的輸出模式
用法: void far setwritemode(int mode);
程序例:
#include
#include
#include
#include
int main()
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int xmax, ymax;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
xmax = getmaxx();
ymax = getmaxy();
/* select XOR drawing mode */
setwritemode(XOR_PUT);
/* draw a line */
line(0, 0, xmax, ymax);
getch();
/* erase the line by drawing over it */
line(0, 0, xmax, ymax);
getch();
/* select overwrite drawing mode */
setwritemode(COPY_PUT);
/* draw a line */
line(0, 0, xmax, ymax);
/* clean up */
getch();
closegraph();
return 0;
}
函數名: signal
功能: 設置某一信號的對應動作
用法: int signal(int sig, sigfun fname);
程序例:
/* This example installs a signal handler routine for SIGFPE,
catches an integer overflow condition, makes an adjustment
to AX register, and returns. This example program MAY cause
your computer to crash, and will produce runtime errors
depending on which memory model is used.
*/
#pragma inline
#include
#include
void Catcher(int sig, int type, int *reglist)
{
printf("Caught it!\n");
*(reglist + 8) = 3; /* make return AX = 3 */
}
int main(void)
{
signal(SIGFPE, Catcher);
asm mov ax,07FFFH /* AX = 32767 */
asm inc ax /* cause overflow */
asm into /* activate handler */
/* The handler set AX to 3 on return. If that hadn't happened,
there would have been another exception when the next 'into'
was executed after the 'dec' instruction. */
asm dec ax /* no overflow now */
asm into /* doesn't activate */
return 0;
}
函數名: sin
功能: 正弦函數
用法: double sin(double x);
程序例:
#include
#include
int main(void)
{
double result, x = 0.5;
result = sin(x);
printf("The sin() of %lf is %lf\n", x, result);
return 0;
}
函數名: sinh
功能: 雙曲正弦函數
用法: double sinh(double x);
程序例:
#include
#include
int main(void)
{
double result, x = 0.5;
result = sinh(x);
printf("The hyperbolic sin() of %lf is %lf\n", x, result);
return 0;
}
函數名: sleep
功能: 執行掛起一段時間
用法: unsigned sleep(unsigned seconds);
程序例:
#include
#include
int main(void)
{
int i;
for (i=1; i<5; i++)
{
printf("Sleeping for %d seconds\n", i);
sleep(i);
}
return 0;
}
函數名: sopen
功能: 打開一共享文件
用法: int sopen(char *pathname, int access, int shflag, int permiss);
程序例:
#include
#include
#include
#include
#include
#include
int main(void)
{
int handle;
int status;
handle = sopen("c:\\autoexec.bat", O_RDONLY, SH_DENYNO, S_IREAD);
if (!handle)
{
printf("sopen failed\n");
exit(1);
}
status = access("c:\\autoexec.bat", 6);
if (status == 0)
printf("read/write access allowed\n");
else
printf("read/write access not allowed\n");
close(handle);
return 0;
}
函數名: sound
功能: 以指定頻率打開PC揚聲器
用法: void sound(unsigned frequency);
程序例:
/* Emits a 7-Hz tone for 10 seconds.
Your PC may not be able to emit a 7-Hz tone. */
#include
int main(void)
{
sound(7);
delay(10000);
nosound();
return 0;
}
函數名: spawnl
功能: 創建並運行子程序
用法: int spawnl(int mode, char *pathname, char *arg0,
arg1, ... argn, NULL);
程序例:
#include
#include
#include
int main(void)
{
int result;
clrscr();
result = spawnl(P_WAIT, "tcc.exe", NULL);
if (result == -1)
{
perror("Error from spawnl");
exit(1);
}
return 0;
}
函數名: spawnle
功能: 創建並運行子程序
用法: int spawnle(int mode, char *pathname, char *arg0,
arg1,..., argn, NULL);
程序例:
/* spawnle() example */
#include
#include
#include
int main(void)
{
int result;
clrscr();
result = spawnle(P_WAIT, "tcc.exe", NULL, NULL);
if (result == -1)
{
perror("Error from spawnle");
exit(1);
}
return 0;
}
函數名: sprintf
功能: 送格式化輸出到字符串中
用法: int sprintf(char *string, char *farmat [,argument,...]);
程序例:
#include
#include
int main(void)
{
char buffer[80];
sprintf(buffer, "An approximation of Pi is %f\n", M_PI);
puts(buffer);
return 0;
}
函數名: sqrt
功能: 計算平方根
用法: double sqrt(double x);
程序例:
#include
#include
int main(void)
{
double x = 4.0, result;
result = sqrt(x);
printf("The square root of %lf is %lf\n", x, result);
return 0;
}
函數名: srand
功能: 初始化隨機數發生器
用法: void srand(unsigned seed);
程序例:
#include
#include
#include
int main(void)
{
int i;
time_t t;
srand((unsigned) time(&t));
printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
printf("%d\n", rand() % 100);
return 0;
}
函數名: sscanf
功能: 執行從字符串中的格式化輸入
用法: int sscanf(char *string, char *format[,argument,...]);
程序例:
#include
#include
int main(void)
{
char label[20];
char name[20];
int entries = 0;
int loop, age;
double salary;
struct Entry_struct
{
char name[20];
int age;
float salary;
} entry[20];
/* Input a label as a string of characters restricting to 20 characters */
printf("\n\nPlease enter a label for the chart: ");
scanf("%20s", label);
fflush(stdin); /* flush the input stream in case of bad input */
/* Input number of entries as an integer */
printf("How many entries will there be? (less than 20) ");
scanf("%d", &entries);
fflush(stdin); /* flush the input stream in case of bad input */
/* input a name restricting input to only letters upper or lower case */
for (loop=0;loop
{
printf("Entry %d\n", loop);
printf(" Name : ");
scanf("%[A-Za-z]", entry[loop].name);
fflush(stdin); /* flush the input stream in case of bad input */
/* input an age as an integer */
printf(" Age : ");
scanf("%d", &entry[loop].age);
fflush(stdin); /* flush the input stream in case of bad input */
/* input a salary as a float */
printf(" Salary : ");
scanf("%f", &entry[loop].salary);
fflush(stdin); /* flush the input stream in case of bad input */
}
/* Input a name, age and salary as a string, integer, and double */
printf("\nPlease enter your name, age and salary\n");
scanf("%20s %d %lf", name, &age, &salary);
/* Print out the data that was input */
printf("\n\nTable %s\n",label);
printf("Compiled by %s age %d $%15.2lf\n", name, age, salary);
printf("-----------------------------------------------------\n");
for (loop=0;loop
printf("%4d | %-20s | %5d | %15.2lf\n",
loop + 1,
entry[loop].name,
entry[loop].age,
entry[loop].salary);
printf("-----------------------------------------------------\n");
return 0;
}
函數名: stat
功能: 讀取打開文件信息
用法: int stat(char *pathname, struct stat *buff);
程序例:
#include
#include
#include
#define FILENAME "TEST.$$$"
int main(void)
{
struct stat statbuf;
FILE *stream;
/* open a file for update */
if ((stream = fopen(FILENAME, "w+")) == NULL)
{
fprintf(stderr, "Cannot open output file.\n");
return(1);
}
/* get information about the file */
stat(FILENAME, &statbuf);
fclose(stream);
/* display the information returned */
if (statbuf.st_mode & S_IFCHR)
printf("Handle refers to a device.\n");
if (statbuf.st_mode & S_IFREG)
printf("Handle refers to an ordinary file.\n");
if (statbuf.st_mode & S_IREAD)
printf("User has read permission on file.\n");
if (statbuf.st_mode & S_IWRITE)
printf("User has write permission on file.\n");
printf("Drive letter of file: %c\n", 'A'+statbuf.st_dev);
printf("Size of file in bytes: %ld\n", statbuf.st_size);
printf("Time file last opened: %s\n", ctime(&statbuf.st_ctime));
return 0;
}
函數名: _status87
功能: 取浮點狀態
用法: unsigned int _status87(void);
程序例:
#include
#include
int main(void)
{
float x;
double y = 1.5e-100;
printf("Status 87 before error: %x\n", _status87());
x = y; /* <-- force an error to occur */
y = x;
printf("Status 87 after error : %x\n", _status87());
return 0;
}
函數名: stime
功能: 設置時間
用法: int stime(long *tp);
程序例:
#include
#include
#include
int main(void)
{
time_t t;
struct tm *area;
t = time(NULL);
area = localtime(&t);
printf("Number of seconds since 1/1/1970 is: %ld\n", t);
printf("Local time is: %s", asctime(area));
t++;
area = localtime(&t);
printf("Add a second: %s", asctime(area));
t += 60;
area = localtime(&t);
printf("Add a minute: %s", asctime(area));
t += 3600;
area = localtime(&t);
printf("Add an hour: %s", asctime(area));
t += 86400L;
area = localtime(&t);
printf("Add a day: %s", asctime(area));
t += 2592000L;
area = localtime(&t);
printf("Add a month: %s", asctime(area));
t += 31536000L;
area = localtime(&t);
printf("Add a year: %s", asctime(area));
return 0;
}
函數名: stpcpy
功能: 拷貝一個字符串到另一個
用法: char *stpcpy(char *destin, char *source);
程序例:
#include
#include
int main(void)
{
char string[10];
char *str1 = "abcdefghi";
stpcpy(string, str1);
printf("%s\n", string);
return 0;
}
函數名: strcat
功能: 字符串拼接函數
用法: char *strcat(char *destin, char *source);
程序例:
#include
#include
int main(void)
{
char destination[25];
char *blank = " ", *c = "C++", *Borland = "Borland";
strcpy(destination, Borland);
strcat(destination, blank);
strcat(destination, c);
printf("%s\n", destination);
return 0;
}
函數名: strchr
功能: 在一個串中查找給定字符的第一個匹配之處\
用法: char *strchr(char *str, char c);
程序例:
#include
#include
int main(void)
{
char string[15];
char *ptr, c = 'r';
strcpy(string, "This is a string");
ptr = strchr(string, c);
if (ptr)
printf("The character %c is at position: %d\n", c, ptr-string);
else
printf("The character was not found\n");
return 0;
}
函數名: strcmp
功能: 串比較
用法: int strcmp(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char *buf1 = "aaa", *buf2 = "bbb", *buf3 = "ccc";
int ptr;
ptr = strcmp(buf2, buf1);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
else
printf("buffer 2 is less than buffer 1\n");
ptr = strcmp(buf2, buf3);
if (ptr > 0)
printf("buffer 2 is greater than buffer 3\n");
else
printf("buffer 2 is less than buffer 3\n");
return 0;
}
函數名: strncmpi
功能: 將一個串中的一部分與另一個串比較, 不管大小寫
用法: int strncmpi(char *str1, char *str2, unsigned maxlen);
程序例:
#include
#include
int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;
ptr = strcmpi(buf2, buf1);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");
if (ptr == 0)
printf("buffer 2 equals buffer 1\n");
return 0;
}
函數名: strcpy
功能: 串拷貝
用法: char *strcpy(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char string[10];
char *str1 = "abcdefghi";
strcpy(string, str1);
printf("%s\n", string);
return 0;
}
函數名: strcspn
功能: 在串中查找第一個給定字符集內容的段
用法: int strcspn(char *str1, char *str2);
程序例:
#include
#include
#include
int main(void)
{
char *string1 = "1234567890";
char *string2 = "747DC8";
int length;
length = strcspn(string1, string2);
printf("Character where strings intersect is at position %d\n", length);
return 0;
}
函數名: strdup
功能: 將串拷貝到新建的位置處
用法: char *strdup(char *str);
程序例:
#include
#include
#include
int main(void)
{
char *dup_str, *string = "abcde";
dup_str = strdup(string);
printf("%s\n", dup_str);
free(dup_str);
return 0;
}
函數名: stricmp
功能: 以大小寫不敏感方式比較兩個串
用法: int stricmp(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;
ptr = stricmp(buf2, buf1);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");
if (ptr == 0)
printf("buffer 2 equals buffer 1\n");
return 0;
}
函數名: strerror
功能: 返回指向錯誤信息字符串的指針
用法: char *strerror(int errnum);
程序例:
#include
#include
int main(void)
{
char *buffer;
buffer = strerror(errno);
printf("Error: %s\n", buffer);
return 0;
}
函數名: strcmpi
功能: 將一個串與另一個比較, 不管大小寫
用法: int strcmpi(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;
ptr = strcmpi(buf2, buf1);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");
if (ptr == 0)
printf("buffer 2 equals buffer 1\n");
return 0;
}
函數名: strncmp
功能: 串比較
用法: int strncmp(char *str1, char *str2, int maxlen);
程序例:
#include
#include
int main(void)
{
char *buf1 = "aaabbb", *buf2 = "bbbccc", *buf3 = "ccc";
int ptr;
ptr = strncmp(buf2,buf1,3);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
else
printf("buffer 2 is less than buffer 1\n");
ptr = strncmp(buf2,buf3,3);
if (ptr > 0)
printf("buffer 2 is greater than buffer 3\n");
else
printf("buffer 2 is less than buffer 3\n");
return(0);
}
函數名: strncmpi
功能: 把串中的一部分與另一串中的一部分比較, 不管大小寫
用法: int strncmpi(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char *buf1 = "BBBccc", *buf2 = "bbbccc";
int ptr;
ptr = strncmpi(buf2,buf1,3);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");
if (ptr == 0)
printf("buffer 2 equals buffer 1\n");
return 0;
}
函數名: strncpy
功能: 串拷貝
用法: char *strncpy(char *destin, char *source, int maxlen);
程序例:
#include
#include
int main(void)
{
char string[10];
char *str1 = "abcdefghi";
strncpy(string, str1, 3);
string[3] = '\0';
printf("%s\n", string);
return 0;
}
函數名: strnicmp
功能: 不注重大小寫地比較兩個串
用法: int strnicmp(char *str1, char *str2, unsigned maxlen);
程序例:
#include
#include
int main(void)
{
char *buf1 = "BBBccc", *buf2 = "bbbccc";
int ptr;
ptr = strnicmp(buf2, buf1, 3);
if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");
if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");
if (ptr == 0)
printf("buffer 2 equals buffer 1\n");
return 0;
}
函數名: strnset
功能: 將一個串中的所有字符都設為指定字符
用法: char *strnset(char *str, char ch, unsigned n);
程序例:
#include
#include
int main(void)
{
char *string = "abcdefghijklmnopqrstuvwxyz";
char letter = 'x';
printf("string before strnset: %s\n", string);
strnset(string, letter, 13);
printf("string after strnset: %s\n", string);
return 0;
}
函數名: strpbrk
功能: 在串中查找給定字符集中的字符
用法: char *strpbrk(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char *string1 = "abcdefghijklmnopqrstuvwxyz";
char *string2 = "onm";
char *ptr;
ptr = strpbrk(string1, string2);
if (ptr)
printf("strpbrk found first character: %c\n", *ptr);
else
printf("strpbrk didn't find character in set\n");
return 0;
}
函數名: strrchr
功能: 在串中查找指定字符的最後一個出現
用法: char *strrchr(char *str, char c);
程序例:
#include
#include
int main(void)
{
char string[15];
char *ptr, c = 'r';
strcpy(string, "This is a string");
ptr = strrchr(string, c);
if (ptr)
printf("The character %c is at position: %d\n", c, ptr-string);
else
printf("The character was not found\n");
return 0;
}
函數名: strrev
功能: 串倒轉
用法: char *strrev(char *str);
程序例:
#include
#include
int main(void)
{
char *forward = "string";
printf("Before strrev(): %s\n", forward);
strrev(forward);
printf("After strrev(): %s\n", forward);
return 0;
}
函數名: strset
功能: 將一個串中的所有字符都設為指定字符
用法: char *strset(char *str, char c);
程序例:
#include
#include
int main(void)
{
char string[10] = "123456789";
char symbol = 'c';
printf("Before strset(): %s\n", string);
strset(string, symbol);
printf("After strset(): %s\n", string);
return 0;
}
函數名: strspn
功能: 在串中查找指定字符集的子集的第一次出現
用法: int strspn(char *str1, char *str2);
程序例:
#include
#include
#include
int main(void)
{
char *string1 = "1234567890";
char *string2 = "123DC8";
int length;
length = strspn(string1, string2);
printf("Character where strings differ is at position %d\n", length);
return 0;
}
函數名: strstr
功能: 在串中查找指定字符串的第一次出現
用法: char *strstr(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char *str1 = "Borland International", *str2 = "nation", *ptr;
ptr = strstr(str1, str2);
printf("The substring is: %s\n", ptr);
return 0;
}
函數名: strtod
功能: 將字符串轉換為double型值
用法: double strtod(char *str, char **endptr);
程序例:
#include
#include
int main(void)
{
char input[80], *endptr;
double value;
printf("Enter a floating point number:");
gets(input);
value = strtod(input, &endptr);
printf("The string is %s the number is %lf\n", input, value);
return 0;
}
函數名: strtok
功能: 查找由在第二個串中指定的分界符分隔開的單詞
用法: char *strtok(char *str1, char *str2);
程序例:
#include
#include
int main(void)
{
char input[16] = "abc,d";
char *p;
/* strtok places a NULL terminator
in front of the token, if found */
p = strtok(input, ",");
if (p) printf("%s\n", p);
/* A second call to strtok using a NULL
as the first parameter returns a pointer
to the character following the token */
p = strtok(NULL, ",");
if (p) printf("%s\n", p);
return 0;
}
函數名: strtol
功能: 將串轉換為長整數
用法: long strtol(char *str, char **endptr, int base);
程序例:
#include
#include
int main(void)
{
char *string = "87654321", *endptr;
long lnumber;
/* strtol converts string to long integer */
lnumber = strtol(string, &endptr, 10);
printf("string = %s long = %ld\n", string, lnumber);
return 0;
}
函數名: strupr
功能: 將串中的小寫字母轉換為大寫字母
用法: char *strupr(char *str);
程序例:
#include
#include
int main(void)
{
char *string = "abcdefghijklmnopqrstuvwxyz", *ptr;
/* converts string to upper case characters */
ptr = strupr(string);
printf("%s\n", ptr);
return 0;
}
函數名: swab
功能: 交換字節
用法: void swab (char *from, char *to, int nbytes);
程序例:
#include
#include
#include
char source[15] = "rFna koBlrna d";
char target[15];
int main(void)
{
swab(source, target, strlen(source));
printf("This is target: %s\n", target);
return 0;
}
函數名: system
功能: 發出一個DOS命令
用法: int system(char *command);
程序例:
#include
#include
int main(void)
{
printf("About to spawn command.com and run a DOS command\n");
system("dir");
return 0;
}
