單片機學習庫函數(shù)詳解

PICCPICC編譯器的庫函數(shù)。每個函數(shù)均從函數(shù)名開始，然后按照以下PICCPICC編譯器的庫函數(shù)。每個函數(shù)均從函數(shù)名開始，然后按照以下例程：給出一個能說明該函數(shù)的應用例參閱：給出相關聯(lián)的函數(shù)返回值：如果函數(shù)有返回值，則在本標題下將給出返回值的類型和性質，同時還包括 ABS#includeintabs(int例#include<stdio.h>#include<stdlib.h>main{inta=-printf("Theabsolutevalueof%dis}返回j ACOS#includedoubleacos(double3.1#includemain{floatfor(i=-1.0，i<1.0；i+={a=acos(i)*180.0/3.141592；}}參sin()，cos()，tan()，asin()，atan()，atan2(返回返回值將為0。 ASCTIME#includechar*asctime(structtm*asctime()t從上structtm結構體中獲得時間，返回描述當前日期和時SunSep1601:03:52當前時間，通過localtime()函數(shù)將其轉換成一個structtm指針，最后轉換成ASCII碼并打印出來。其中，time()函數(shù)需要用戶提供（詳情請參閱time()函數(shù)。3.#include<stdio.h>#include<time.h>main{time_tclock；structtm*tp；tp=2}參ctime()，gmtime()，localtime()，time(返回注意：由于編譯器不提供time(例行程序，故在本例程中它需要由用戶提供。詳情請參照time(數(shù)據(jù)類structtminttm_sec；inttm_min；inttm_hour；inttm_mon；inttm_year；inttm_wday；inttm_yday；inttm_isdst； ASIN#includedoubleasin(doubleasin(函數(shù)是sin的反函數(shù)。它的函數(shù)參數(shù)在[-1，1]區(qū)間內(nèi)，返回一個用弧度表示3.#include<math.h>#include<stdio.h>main{floatfor(i=-1.0；i<1.0；i+={a=asin(i)*180.0/3.141592；}}3參sin()，cos()，tan()參sin()，cos()，tan()，acos()，atan()，atan2(返回 ATAN#includedoubleatan(double例#include<stdio.h>#include<math.h>main{}參sin()，cos()，tan()，asin()，acos()，atan2(返回 ATAN2#includedoubleatan2(doubley，double例#include<stdio.h>#include<math.h>main{}參4sin()，cos()，tan()，sin()，cos()，tan()，asin()，acos()，atan(5.回 ATOF#includedoubleatof(constchar*()例#include<stdlib.h>#include<stdio.h>main{doublei；i=printf("Read%s:convertedto}參atoi()，atol(返回 ATOI#includeintatoi(constchar*atoi(函數(shù)掃描傳遞過來的字符串，跳過開頭的空格并讀取其符號;然后將一個十進3.#include<stdio.h>5main{intimain{inti；i=printf("Read%s:convertedto}參xtoi()，atof()，atol(返回 ATOL#includelongatol(constchar*atol(函數(shù)掃描傳遞過來的字符串，并跳過字符串開頭的空格；然后將十進制數(shù)的例#include<stdio.h>main{longi；i=printf("Read%s:convertedto}參atoi()，atof(返回返回一個長整型數(shù)。如果字符串中沒有發(fā)現(xiàn)任何數(shù)字，返回值為0CEIL#include6doubleceil(doublef取整，取整后的返回值為大于或等于例程#include<stdio.h>#includedoubleceil(doublef取整，取整后的返回值為大于或等于例程#include<stdio.h>#include<math.h>main{doublej；scanf("%lf"，printf("Theceilingof%lfis} COS#includedoublecos(double例#include<math.h>#include<stdio.h>main{doublefor(i=0；i<=180.0；i+=printf("sin(%3.0f)=%f，cos=}參sin()，tan()，asin()，acos()，atan()，atan2(返回COSH、SINH、TANH#includedoublecosh(double7doublesinh(doubledoubletanh(doubledoublesinh(doubledoubletanh(double例#include<stdio.h>#include<math.h>main{}返回cosh()函數(shù)返回雙曲余弦值，sinh()函數(shù)返回雙曲正弦值，tanh()函數(shù)返回雙曲正CTIME#includechar*ctime(time_t*))例#include<stdio.h>#include<time.h>main{time_tclock；}參gmtime()，localtime()，asctime()，time(返回注意：由于編譯器不會提供time(程序，故它需要由用戶給定。詳情請參閱time(數(shù)據(jù)類8typedeflong DI、EItypedeflong DI、EIvoidei(void)void的連續(xù)字期間出現(xiàn)中斷，則函數(shù)getticks()例longcount；voidinterrupt{}long{di()；ei()；returnval；}DIV#includediv_tdiv(intnumer，int)例#include<stdio.h>main{9div_tx=div_tx=printf("quotient=%d，remainder=}返回數(shù)據(jù)類typedef{int} EEPROM_READ、EEPROM_WRITE#includeunsignedchareeprom_read(unsignedcharvoideeprom_write(unsignedcharaddr，unsignedcharEEPROM3.main{unsignedchardata；address=0x10；data=}注意：如果調(diào)用eeprom_write()函數(shù)后需即刻調(diào)用eeprom_read()函數(shù)，則必須查詢EEPROM以確保寫入完畢。全局中斷使能位（GIE）在eeprom_write(程序中重新恢復（寫EEPROM時需要關閉EVAL_POLY#includedoubleeval_poly(doublex，const#includedoubleeval_poly(doublex，constdouble*d，inty=x*x*d2+x*d1+例#include<stdio.h>#include<math.h>main{doublex=2.2；y=printf("Thepolynomialevaluatedat%fis}返回EXP#includedoubleexp(doubleexp(函數(shù)返回參數(shù)的指數(shù)函數(shù)值，即ef（f為函數(shù)參數(shù)例#include<math.h>#include<stdio.h>main{doublefor(f=0.0；f<=5；f+=printf("eto%1.0f=}參log()，log10()，pow(FABS#includedoublefabs(double例FABS#includedoublefabs(double例#include<stdio.h>#include<math.h>main{printf("%f%f\n"，fabs(1.5)，fabs(-}參abs(FLOOR#includedoublefloor(double例#include<stdio.h>#include<math.h>main{printf("%f\n"，floor(1.5))；printf("%f\n"，floor(-1.5))；}FREXP#includedoublefrexp(doublef，int*frexp()函數(shù)將一個浮點數(shù)分解成規(guī)格化小數(shù)和2的整數(shù)次冪兩部分，整數(shù)冪部分存于指pint單元中。本函數(shù)的返回值x或在區(qū)間（0.5，1.0）0；而且有f=x×2p。如果f為0，則分解出來的兩部分均為0。例#include<math.h>#include<stdio.h>main{例#include<math.h>#include<stdio.h>main{inti；f=frexp(23456.34，&i)；printf("23456.34=%f*2^%d\n"，f，i)；}參ldexp(GET_CAL_DATA#includedoubleget_cal_data(constunsignedchar*訪問KREF、KBG、BHTHERM和KTC單元（32位浮點參數(shù)。由于FOSC和TWDT例main{doublex；xget_cal_data(KREF)；/*獲得參考斜率（slopereferenceratio）*/y=TWDT；/*獲得WDT溢出時間*/}返回注意：本函數(shù)僅用于PICGMTIME#includestructtm*gmtime(time_t*t所指的時間分解,并且存于結構體中，精確度為秒。其中，tt所指的時間分解,并且存于結構體中，精確度為秒。其中，t例#include<stdio.h>#include<time.h>main{time_tclock；structtm*tp；tp=printf("It’s%dinLondon\n"，tp-}參ctime()，asctime()，time()，localtime(返回注意：由于編譯器不會提供time(程序，故它需要由用戶給定。詳情請參閱time(數(shù)據(jù)類structtm{inttm_sec；inttm_min；inttm_hour；inttm_mon；inttm_year；inttm_wday；inttm_yday；inttm_isdst；等函intisalnum(charc)intisalpha(charc)intisascii(charc)intiscntrl(charintisdigit(charc)intislower(charintisdigit(charc)intislower(charc)intisprint(charc)intisgraph(charc)intispunct(charc)intisspace(charc)intisupper(charintisxdigit(charisalpha(c)isascii(c)iscntrl(c)isdigit(c)islower(c)isprint(c)isgraph(c)ispunct(c)isspace(c)isupper(c)isxdigit3．例#include<ctype.h>#include<stdio.h>main{inti；i=c在0～9、a～f或A～F范圍內(nèi)buf[i]=printf("’%s’isthe}4．參toupper()，tolower()，toascii( KBHIT#includebitkbhit KBHIT#includebitkbhit)例main{inti；cputs("I’mfor(i=0；i!=1000；i++)}}參getch()，getche(返回注意：程序的主體需由用戶實現(xiàn)，其主要框架可以從sources目錄下直接獲得LDEXP#includedoubleldexp(doublef，intldexp函數(shù)是frexp(的反函數(shù)。它先進行浮點數(shù)3.#include<math.h>#include<stdio.h>main{doublef=printf("1.0*2^10=f的指數(shù)部分與整i}參frexp(返回f}參frexp(返回fiLDIV#includeldiv_tldiv(longnumber，long例#include<stdlib.h>#include<stdio.h>main{ldiv_tlt=printf("Quotient=%ld，remainder=}參閱div()數(shù)據(jù)結typedef{longquot/*longrem/*余數(shù) LOCALTIME#includestructtm*localtime(time_t*數(shù)的返回值將與gmtime()的相同。3．例#include<stdio.h>#include<time.h>char*wday[]={main{time_tclock；structtm*tp；tp=printf("Todayis%s\n"，wday[tp-}參ctime()，asctime()，time(返回注意：由于編譯器不會提供time(程序，故它需要由用戶給定。詳情請參閱time(數(shù)據(jù)結structtm{inttm_sec；inttm_min；inttm_hour；inttm_mon；inttm_year；inttm_wday；inttm_yday；inttm_isdst；LOG、LOG10#include<math.h>double#include<math.h>doublelog10(double))例#include<math.h>#include<stdio.h>main{doublefor(f=1.0；f<=10.0；f+=1.0)}參exp()，pow(返回如果函數(shù)參數(shù)為負，返回值為0MEMCHR#include/*constvoid*memchr(constvoid*block，intval，size_t/*高級系列單片機void*memchr(constvoid*block，intval，size_t3.#include<stdio.h>unsignedintary[]={1，5，0x6789，0x23}；main{char*cp=memchr(ary，0x89，sizeofprintf("Foundprintf("Foundatoffset%u\n"，cp-(char}參strchr(返回NULLMEMCMP#includeintmemcmp(constvoid*s1,constvoid*s2,size_tmemcmp()函數(shù)的功能是比較兩塊長度為n的內(nèi)存中變量的大小，類似strncmp()函例#include<stdio.h>main{buf[0]=1;buf[2]=cow[0]=cow[2]=buf[1]=cow[1]=if(i<0)printf("lessthan\n");elseif(i>0)}參strncpy()，strncmp()，strchr()，memset()參strncpy()，strncmp()，strchr()，memset()，返回,1。MEMCPY#include/*void*memcpy(void*d,constvoid*s,size_t/*farvoid*memcpy(farvoid*d,constvoid*s,size_t,例#include<stdio.h>main{charmemset(buf,0,sizeofbuf);memcpy(buf,"apartialstring",10);printf("buf=’%s’\n",buf);}參strncpy()，strncmp()，strchr()，返回MEMMOVE#include/*void*memmove(void*s1,constvoid*s2,size_t/*farvoid*memmove(farvoid*s1,constvoid*s2,size_t參參返回MEMSET#include/**/void*memset(void*sintc,size_t/*farvoid*memset(farvoid*s,intc,size_tmemset()函數(shù)將字節(jié)c存儲到指針s指向的，內(nèi)存開始的n個內(nèi)存字節(jié)例#include<stdio.h>main{charstrcpy(abuf,"Thisisastring");memset(abuf,’x’,5);printf("buf=’%s’\n",}參MODF#includedoublemodf(doublevalue,double*0.173.#includemain{doublei_val,f_valmain{doublei_val,f_val=modf(-3.17,}4.回PERSIST_CHECK,PERSIST_VALIDATE#includeintpersist_check(intflag)voidpersist_validate(void)例#include<sys.h>main{printf("Resetcountinvalid-zeroed\n");reset_count++;/*updatecount*/persist_validate();/*andchecksum*/continue;/*sleepuntilnextreset}返回,（非零POW#includedoublepow(doublef,POW#includedoublepow(doublef,doublepow()函數(shù)表示第一個參數(shù)f的p次冪例#include<math.h>#include<stdio.h>main{doublefor(f=1.0;f<=10.0;f+=printf("pow(2,%1.0f)=%f\n",f,pow(2,}參log(),log10(),返回fpPRINTF#includeunsignedcharprintf(constchar*fmt,（staoutoxXu 例輸出為’Total=23%’printf("Sizeis%lx",size)printf("Name=%.8s",’Nameprintf("xx%*d",3,輸出為’xx/*vprintf*/#includestdio.h>error(char*s,{va_listap;va_start(ap,s);vprintf(s,ap);}main{inti;i=error("testing12%d",}參見sprintf()函數(shù)返回關PICC–L的描述以及有關PICC–L的描述以及有關HPDPIC長整型格式在printf的菜單選項RAND#includeintrand每次被調(diào)用后,以隨機數(shù)據(jù)形式出現(xiàn)。這一運算規(guī)則將產(chǎn)生一個從同一起點開始的確定3.#include<stdio.h>#include<time.h>main{time_ttoc;inti;for(i=0;i!=10;i++)printf("%d\t",rand());}參見srand()函數(shù)SIN#includedoublesin(double3.程#include<math.h>#include<stdio.h>main{doublefor(i=0;main{doublefor(i=0;i<=180.0;i+=printf("sin(%3.0f)=%f,cos=%f\n",i,sin(i*C),}參cos(),tan(),asin(),acos(),atan(),返回SPRINTF#include/*unsignedcharsprintf(char*buf,constchar*fmt,/*unsignedcharsprintf(farchar*buf,constchar*fmt,;被放到buf緩沖器。字符串帶有空格結束符，buf緩沖器中的數(shù)據(jù)被返回。參見printf()返回sprintf()函數(shù)的返回值為被放入緩沖器中的數(shù)據(jù)。注意，返回值為字符型而非整型SQRT#includedoublesqrt(doublesqrt()函數(shù)利用牛頓法得到參數(shù)的近似平例#include<math.h>#include<stdio.h>main{doublefor(i=0;i<=20.0;i+=printf("squarerootof%.1f=%f\n",i,}參見exp()4.回SRAND參見exp()4.回SRAND#includevoidsrand(unsignedintsrand()函數(shù)是在調(diào)用rand()函數(shù)時被用來初始化隨機數(shù)據(jù)發(fā)生器的。它為rand()函數(shù)產(chǎn)3.#include<stdio.h>#include<time.h>main{time_ttoc;inti;for(i=0;i!=10;i++)printf("%d\t",rand());}STRCAT#include/*char*strcat(char*s1,constchar*/*farchar*strcat(farchar*s1,constchar*針型參數(shù)s1指向的字符數(shù)組必須保證大于結果字符串。3.#include<stdio.h>main{#include<stdio.h>main{char*s1,*s2;s1=buffer;s2="...endofline";strcat(s1,s2);printf("string=\"%s\"\n",buffer);}參strcpy(),strcmp(),strncat(),返回STRCHR,STRICHR#include/*constchar*strchr(constchar*s,intc)constchar*strichr(constchar*s,int/*char*strchr(constchar*s,intchar*strichr(constchar*s,intstrchr()函數(shù)查找sc。如果找到了3.#include<stdio.h>main{staticchartemp[]="Hereitis...";charc=’s’;if(strchr(temp,printf("Character%cwasfoundinstring\n",printf("Nocharacterwasfoundin}參printf("Nocharacterwasfoundin}參strrchr(),strlen(),返回STRCMP,STRICMP#includeintstrcmp(constchar*s1,constchar*s2)intstricmp(constchar*s1,constchar*是否小于、等于或大于字符串s2，返回一個有符號整數(shù)。比較是字母的順例#include<stdio.h>main{intif((i=strcmp("ABC","ABc"))<0)printf("ABCislessthanABc\n");elseif(i>0)printf("ABCisequalto}參strlen(),strncmp(),strcpy(),返回-11STRCPY#include/*char*strcpy#include/*char*strcpy(char*s1,constchar*/*farchar*strcpy(farchar*s1,constchar*例#include<stdio.h>main{char*s1,*s2;s1=buffer;s2="...endofline";strcat(s1,s2);printf("Length=%d\n",printf("string=\"%s\"\n",}參strncpy(),strlen(),strcat(),返回STRCSPN#includesize_tstrcspn(constchar*s1,constchar*例#include<stdio.h>main{staticcharset[]=printf("%d\n",strcspn("xxxbcadefs",set));printf("%d\n",strcspn("1234567890",}printf("%d\n",strcspn("xxxbcadefs",set));printf("%d\n",strcspn("1234567890",}參見strspn()函數(shù)4.回STRLEN#includesize_tstrlen(constchar*例#include<stdio.h>main{char*s1,*s2;s1=buffer;s2="...endofline";strcat(s1,s2);printf("string=\"%s\"\n",buffer);}返回STRNCAT#include/*char*strncat(char*s1,constchar*s2,size_t/*farchar*strncat(farchar*s1,constchar*s2,size_t例例#include<stdio.h>main{char*s1,*s2;s1=buffer;s2="...endofline";strncat(s1,s2,5);printf("string=\"%s\"\n",buffer);}參strcpy(),strcmp(),strcat(),返回,#includeintstrncmp(constchar*s1,constchar*s2,size_tn)intstrnicmp(constchar*s1,constchar*s2,size_t3.#include<stdio.h>main{intif(i==0)printf("Bothstringsareelseif(i>printf("String2elseif(i>printf("String2lessthanstring1\n");printf("String2isgreaterthanstring}參strlen(),strcmp(),strcpy(),返回注意：其它C應用函數(shù)可以采用不同的字母順序。返回值為負、零或正，并不一定是-1或1STRNCPY#include/*char*strncpy(char*s1,constchar*s2,size_t/*farchar*strncpy(farchar*s1,constchar*s2,size_t這個函數(shù)將帶結束符的字符串s2拷貝到字符指針s1指向的字符數(shù)組。最多有n例#include<stdio.h>main{char*s1,*s2;s1=buffer;s2="...endofline";strcat(s1,s2);printf("string=\"%s\"\n",buffer);}參strcpy(),strcat(),strlen(),返回指針s1指向的目的STRPBRK#include/*constSTRPBRK#include/*constchar*strpbrk(constchar*s1,constchar*/*char*strpbrk(constchar*s1,constchar*例#include<stdio.h>main{char*str="Thisisastring.";while(str!=NULL){printf("%s\n",strstr=strpbrk(str+1,"aeiou"}}返回#include/*中級和低級系列單片機*/constchar*strrchr(char*sintc)constchar*strrichr(char*sint/*char*strrchr(char*s,intchar*strrichr(char*s,intstrrchr()函數(shù)完全一樣。3.#include<stdio.h>#includemain{char*str=main{char*str="Thisisastring.";while(str!=NULL){printf("%s\n",strstr=strrchr(str+1,}}參strchr(),strlen(),strcmp(),strcpy(),返回STRSPN#includesize_tstrspn(constchar*s1,constchar*strspn()函數(shù)返回字符串s1中包含的、完全由字符串s2組成的字符的例#include<stdio.h>main{printf("%d\n",strspn("Thisisastring","This"));printf("%d\n",strspn("Thisisastring",}參見strcspn()函數(shù)4.回 STRSTR,STRISTR#include/*constchar*strstr(constchar*s1,constchar*s2)constchar*stristr(constchar*s1,constchar*/*char*strstr(constchar*s1,constchar*char*strist