C语言函数大全(s开头)(2)

副标题#e#

函数名: setvisualpage

成果: 配置可见图形页号

用法: void far setvisualpage(int pagenum);

措施例:

#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;
}

#p#副标题#e#

函数名: setwritemode

成果: 配置图形方法下画线的输出模式

用法: void far setwritemode(int mode);

措施例:

#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;
}

#p#副标题#e#

函数名: signal

成果: 配置某一信号的对应行动

用法: int signal(int sig, sigfun fname);

措施例:

/* 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;
}

函数名: sin

成果: 正弦函数

用法: double sin(double x);

措施例:

#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;
}

#p#副标题#e#

函数名: sinh

成果: 双曲正弦函数

用法: double sinh(double x);

措施例:

#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;
}

函数名: sleep

成果: 执行挂起一段时间

用法: unsigned sleep(unsigned seconds);

措施例:

#include
#include
int main(void)
{
int i;
for (i=1; i<5; i++)
{
printf("Sleeping for %d seconds\n", i);
sleep(i);
}
return 0;
}

#p#副标题#e#

函数名: sopen

成果: 打开一共享文件

用法: int sopen(char *pathname, int access, int shflag, int permiss);

措施例:

#p#分页标题#e#

#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;
}

函数名: sound

成果: 以指定频率打开PC扬声器

用法: void sound(unsigned frequency);

措施例:

/* 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;
}

#p#副标题#e#

函数名: spawnl

成果: 建设并运行子措施

用法: int spawnl(int mode, char *pathname, char *arg0,

arg1, … argn, NULL);

措施例:

#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;
}

函数名: spawnle

成果: 建设并运行子措施

用法: int spawnle(int mode, char *pathname, char *arg0,

arg1,…, argn, NULL);

措施例:

/* 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;
}

#p#副标题#e#

函数名: sprintf

成果: 送名目化输出到字符串中

用法: int sprintf(char *string, char *farmat [,argument,…]);

措施例:

#include
#include
int main(void)
{
char buffer[80];
sprintf(buffer, "An approximation of Pi is %f\n", M_PI);
puts(buffer);
return 0;
}

函数名: sqrt

成果: 计较平方根

用法: double sqrt(double x);

措施例:

#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;
}

函数名: srand

成果: 初始化随机数产生器

用法: void srand(unsigned seed);

措施例:

#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;
}

#p#副标题#e#

函数名: sscanf

成果: 执行从字符串中的名目化输入

用法: int sscanf(char *string, char *format[,argument,…]);

措施例:

#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;
}

#p#副标题#e#

函数名: stat

成果: 读取打开文件信息

用法: int stat(char *pathname, struct stat *buff);

措施例:

#p#分页标题#e#

#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;
}

函数名: _status87

成果: 取浮点状态

用法: unsigned int _status87(void);

措施例:

#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;
}

#p#副标题#e#

函数名: stime

成果: 配置时间

用法: int stime(long *tp);

措施例:

#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;
}

函数名: stpcpy

成果: 拷贝一个字符串到另一个

用法: char *stpcpy(char *destin, char *source);

措施例:

#include
#include
int main(void)
{
char string[10];
char *str1 = "abcdefghi";
stpcpy(string, str1);
printf("%s\n", string);
return 0;
}

#p#副标题#e#

函数名: strcat

成果: 字符串拼接函数

用法: char *strcat(char *destin, char *source);

措施例:

#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;
}

函数名: strchr

成果: 在一个串中查找给定字符的第一个匹配之处\

用法: char *strchr(char *str, char c);

措施例:

#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;
}

函数名: strcmp

成果: 串较量

用法: int strcmp(char *str1, char *str2);

措施例:

#p#分页标题#e#

#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;
}

#p#副标题#e#

函数名: strncmpi

成果: 将一个串中的一部门与另一个串较量, 不管巨细写

用法: int strncmpi(char *str1, char *str2, unsigned maxlen);

措施例:

#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;
}

函数名: strcpy

成果: 串拷贝

用法: char *strcpy(char *str1, char *str2);

措施例:

#include
#include
int main(void)
{
char string[10];
char *str1 = "abcdefghi";
strcpy(string, str1);
printf("%s\n", string);
return 0;
}

函数名: strcspn

成果: 在串中查找第一个给定字符集内容的段

用法: int strcspn(char *str1, char *str2);

措施例:

#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;
}

#p#副标题#e#

函数名: strdup

成果: 将串拷贝到新建的位置处

用法: char *strdup(char *str);

措施例:

#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;
}

函数名: stricmp

成果: 以巨细写不敏感方法较量两个串

用法: int stricmp(char *str1, char *str2);

措施例:

#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;
}

函数名: strerror

成果: 返回指向错误信息字符串的指针

用法: char *strerror(int errnum);

措施例:

#include
#include
int main(void)
{
char *buffer;
buffer = strerror(errno);
printf("Error: %s\n", buffer);
return 0;
}

#p#副标题#e#

函数名: strcmpi

成果: 将一个串与另一个较量, 不管巨细写

用法: int strcmpi(char *str1, char *str2);

措施例:

#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;
}

函数名: strncmp

成果: 串较量

用法: int strncmp(char *str1, char *str2, int maxlen);

措施例:

#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);
}

#p#副标题#e#

函数名: strncmpi

成果: 把串中的一部门与另一串中的一部门较量, 不管巨细写

用法: int strncmpi(char *str1, char *str2);

措施例:

#p#分页标题#e#

#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;
}

函数名: strncpy

成果: 串拷贝

用法: char *strncpy(char *destin, char *source, int maxlen);

措施例:

#include
#include
int main(void)
{
char string[10];
char *str1 = "abcdefghi";
strncpy(string, str1, 3);
string[3] = '\0';
printf("%s\n", string);
return 0;
}

#p#副标题#e#

函数名: strnicmp

成果: 不注重巨细写地较量两个串

用法: int strnicmp(char *str1, char *str2, unsigned maxlen);

措施例:

#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;
}

函数名: strnset

成果: 将一个串中的所有字符都设为指定字符

用法: char *strnset(char *str, char ch, unsigned n);

措施例:

#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;
}

函数名: strpbrk

成果: 在串中查找给定字符会合的字符

用法: char *strpbrk(char *str1, char *str2);

措施例:

#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;
}

函数名: strrchr

成果: 在串中查找指定字符的最后一个呈现

用法: char *strrchr(char *str, char c);

措施例:

#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;
}

函数名: strrev

成果: 串倒转

用法: char *strrev(char *str);

措施例:

#include
#include
int main(void)
{
char *forward = "string";
printf("Before strrev(): %s\n", forward);
strrev(forward);
printf("After strrev(): %s\n", forward);
return 0;
}

#p#副标题#e#

函数名: strset

成果: 将一个串中的所有字符都设为指定字符

用法: char *strset(char *str, char c);

措施例:

#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;
}

函数名: strspn

成果: 在串中查找指定字符集的子集的第一次呈现

用法: int strspn(char *str1, char *str2);

措施例:

#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;
}

函数名: strstr

成果: 在串中查找指定字符串的第一次呈现

用法: char *strstr(char *str1, char *str2);

措施例:

#p#分页标题#e#

#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;
}

#p#副标题#e#

函数名: strtod

成果: 将字符串转换为double型值

用法: double strtod(char *str, char **endptr);

措施例:

#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;
}

函数名: strtok

成果: 查找由在第二个串中指定的分界符脱离开的单词

用法: char *strtok(char *str1, char *str2);

措施例:

#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;
}

函数名: strtol

成果: 将串转换为长整数

用法: long strtol(char *str, char **endptr, int base);

措施例:

#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;
}

函数名: strupr

成果: 将串中的小写字母转换为大写字母

用法: char *strupr(char *str);

措施例:

#include
#include
int main(void)
{
char *string = "abcdefghijklmnopqrstuvwxyz", *ptr;
/* converts string to upper case characters */
ptr = strupr(string);
printf("%s\n", ptr);
return 0;
}

函数名: swab

成果: 互换字节

用法: void swab (char *from, char *to, int nbytes);

措施例:

#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;
}

函数名: system

成果: 发出一个DOS呼吁

用法: int system(char *command);

措施例:

#include
#include
int main(void)
{
printf("About to spawn command.com and run a DOS command\n");
system("dir");
return 0;
}