C语言库函数(R类字母).txt

文档介绍：函数名: raise
功能: 向正在执行的程序发送一个信号
用法: int raise(int sig);
程序例:
#include <>
int main(void)
{
int a, b;
a = 10;
b = 0;
if (b == 0)
/* preempt divide by zero error */
raise(SIGFPE);
a = a / b;
return 0;
}
函数名: rand
功能: 随机数发生器
用法: void rand(void);
程序例:
#include <>
#include <>
int main(void)
{
int i;
printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
printf("%d\n", rand() % 100);
return 0;
}
函数名: randbrd
功能: 随机块读
用法: int randbrd(struct fcb *fcbptr, int t);
程序例:
#include <>
#include <>
#include <>
#include <>
int main(void)
{
char far *save_dta;
char line[80], buffer[256];
struct fcb blk;
int i, result;
/* get user input file name for dta */
printf("Enter drive and file name (no path - . a:)\n");
gets(line);
/* put file name in fcb */
if (!parsfnm(line, &blk, 1))
{
printf("Error in call to parsfnm\n");
exit(1);
}
printf("Drive #%d File: %s\n\n", , );
/* open file with DOS FCB open file */
bdosptr(0x0F, &blk, 0);
/* save old dta, and set new one */
save_dta = getdta();
setdta(buffer);
/* set up info for the new dta */
= 128;
= 0L;
result = randbrd(&blk, 1);
/* check results from randbrd */
if (!result)
printf("Read OK\n\n");
else
{
perror("Error during read");
exit(1);
}
/* read in data from the new dta */
printf("The first 128 characters are:\n");
for (i=0; i<128; i++)
putchar(buffer[i]);
/* restore previous dta */
setdta(save_dta);
return 0;
}
函数名: randbwr
功能: 随机块写
用法: int randbwr(struct fcp *fcbptr, int t);
程序例:
#include <>
#include <>
#include <>
#include <>
int main(void)
{
char far *save_dta;
char line[80];
char buffer[256] = "RANDBWR test!";
struct fcb blk;
int result;
/* get new file name from user */
printf("Enter a file name to create (no path - ie. a:\n");
gets(line);
/* parse the new file name to the