華閱文章網C++中有peek函數來觀察下一個字符,在C中有沒有對應功能的函數啊
C中沒有peek.
C 的讀語句能返回 成功讀入的變量個數，通過判斷 成功讀入的變量個數就知道 是否 讀入成功，是否 到了 EOF.
C 的 fgetc 可以 讀 下一個字符，如果想 把文件指針 退回一個字符，（等價與peek操作）可以這樣做：
FILE *fin;
void main()
{
char s1[80],s2[80];
int c;
fpos_t pos;
fin = fopen("*","r")； // 打開文件 （文本和2進制都可以）
c=fgetc(fin)； // 讀第一個字符
printf("%c ",c);
fgetpos (fin,&pos)； // 取文件指針位置
c=fgetc(fin)； // 讀第二個字符 -----
printf("%c ",c);
fsetpos (fin,&pos)； // 撥回指針 -----
c=fgetc(fin)； // 重讀第二個字符
printf("%c ",c);
fclose(fin);
}
取文件指針位置，讀（第二個）字符，撥回指針 等于 peek.
c 允許你在任何時候 撥回指針，例如你可以連讀一組數，再撥回指針，重新再讀。
目前世界上生產性能最好的peek（聚醚醚酮）在哪里,好到了很么程？
國際上做PEEK的一般就3個廠商 Victrex Solvay 吉大，前面2家的合成工藝都是一樣的，但是Victrex早些年在中國把 PEEK 注冊了商標，使得Solvay在國內不能出售PEEK，導致在國內一說PEEK就只會聯想到Victrex。
其實兩家實力差不多，各有各的特點。因為PEEK昂貴的價格Solvay還特地為此推出了改性的PEEK，在降低了成本的同時，也滿足了客戶對高性能塑料需求。
國內吉大的PEEK質量比國外的就差的遠了，性能上遠沒有進口的料好。 PEEK材料具有非常好的剛性，耐輻射，耐水解，耐高溫能力，長期使用溫度為250度，廣泛應用于航空航天，醫學，軍事，石油等方面。
介紹該材料的詳細資料在出售該材料的供應商那里較多，因為對于該材料的應用有很大部分是在軍事上，是保密的，所以網上不是很多，供應商可能會了解到一些。 如您需要PEEK粒料可以聯系我，我是做Solvay PEEK粒料的，人在無錫，有需要可以發消息M我。
請告訴我17個Q-BASIC語言命令語句
QBASIC - Statements 命令：BEEP, BLOAD, BSAVE, CALL, CHAIN, CHDIR, CIRCLE, CLEAR, CLOSE, CLS, COLOR, COM, COMMON, CONST, DATA, DATE$, DECLARE, DEF, DEFDBL, DEFINT, DEFLNG, DEFSNG, DEFSTR, DIM, DO, DRAW, END, ENVIRON, ERASE, ERROR, EXIT, FIELD, FILES, FOR, FUNCTION, GET, GOSUB, GOTO, IF, INPUT, IOCTL, KEY, KILL, LET, LINE, LINE INPUT, LOCATE, LOCK, LPRINT, LSET, MID$, MKDIR, NAME, ON, OPEN, OPTION, OUT, PAINT, PALETTE, PCOPY, PEN, PLAY, POKE, PRESET, PRINT, PSET, PUT, RANDOMIZE, READ, REDIM, REM, RESET, RESTORE, RESUME, RETURN, RMDIR, RSET, RUN, SCREEN, SEEK, SELECT CASE, SHARED, SHELL, SLEEP, SOUND, STATIC, STOP, STRIG, SUB, SWAP, SYSTEM, TIME$, TROFF, TRON, TYPE, UNLOCK, VIEW, WAIT, WHILE, WIDTH, WINDOW, WRITE程序： CALL CHAIN DECLARE END OPTION REM RUN STOP事件： ON SLEEP WAIT結構： DO ERROR EXIT FOR FUNCTION GOSUB GOTO IF RESUME RETURN SELECT CASE SUB WHILE數據 CLEAR COMMON CONST DATA DEFDBL DEFINT DEFLNG DEFSNG DEFSTR DIM ERASE INPUT LET MID$ RANDOMIZE READ REDIM RESTORE SHARED SWAP STATIC TYPEPen PENJoystick STRIGKeyboard INPUT KEY LINE INPUTScreen CLS COLOR LOCATE PALETTE PCOPY PRINT SCREEN VIEW WIDTH WINDOWPrinter LPRINT WIDTHGraphics CIRCLE DRAW GET LINE PAINT PRESET PSET PUTSound BEEP PLAY SOUNDMemory BLOAD BSAVE CLEAR DEF DEF SEG POKEFile CLOSE KILL NAME OPEN RESETSequential file INPUT LINE INPUT PRINT WRITERandom file FIELD GET LOCK LSET PUT RSET SEEK UNLOCKBinary file BLOAD BSAVEDirectory CHDIR MKDIR RMDIRSystem COM ENVIRON IOCTL OUT SHELL SYSTEMDate & Time DATE$ TIME$Debug TROFF TRONBEEP Sounds the speaker at 800 Hz for 1/4 second. PRINT CHR$(7) also beepsCIRCLE >SCREEN 1: CIRCLECLOSE Close an open file >OPENDATA >maskinkode: arrayDEFDEF SEG Sets the current segment address. DEF SEG [=address] address A segment address used by BLOAD, BSAVE, CALL ABSOLUTE, PEEK, or POKE - a value in the range 0 - 65535. If address is omitted, DEF SEG resets the current segment address to the default data *e: DEF SEG = 0 Status% = PEEK(&H417) POKE &H417, (Status% XOR &H40) DEF SEGRead keyboard status. Change Caps Lock state, bit 6. Reset segment address.>maskinkode: arrayDIM DIM declares an array or specifies a data type for a nonarray variable. >REDIM, $DYNAMIC, $STATIC DIM [SHARED] variable[(subscripts)] [AS type][, variable[(subscripts)] [AS type]]。
SHARED Specifies that variables are shared with all SUB or FUNCTION procedures in the module. subscripts Dimensions of the array, expressed as follows: [lower TO] upper [, [lower TO] upper]。 lower The lower bound of the array's subscripts. The default lower bound is zero. upper The upper bound. >OPTION BASE AS type Declares the data type of the array or variable: INTEGER A 16-bit signed integer variable LONG A 32-bit signed integer variable SINGLE A single-precision 32-bit floating-point variable DOUBLE A double-precision 64-bit floating-point variable STRING * n% A fixed-length string variable n% bytes long STRING A variable-length string variableDIM i% DIM i AS INTEGER DIM s AS STRING * 20 DIM a(4) AS SINGLE '5 numbers (0 to 4)DRAW > SCREEN 1: DRAWGET >GET [File I/O] >GET [Graphics]IF。
THEN。ELSE IF condition THEN statements [ELSE statements] IF condition THEN statements [ELSEIF condition THEN statements]。
[ELSE statements] END IFKEY >KEY [Assignment] >KEY [Event Trapping]LINE (Graphics) > SCREEN 1: LINELOCATE > SCREEN 0: LOCATE (show/hide/define cursor)LPRINT > Printer: LPRINT > PRINTMID$ The MID$ statement replaces part of a string variable with another string. MID$(stringvariable$,start%[,length%])=stringexpression$ stringvariable$ The string variable being modified. start% The position of the first character in the substring being replaced. length% The number of characters in the substring. If the length is omitted, MID$ replaces all characters to the right of the start position. stringexpression$ The replacement string. It can be any string expression. Ex: Text$ = "Paris, France" PRINT Text$ MID$(Text$, 8) = "Texas " PRINT Text$ Paris, France Paris, Texas >Function: MID$()PAINT > SCREEN 1: PAINTPALETTE > SCREEN 1: PALETTEPLAY 。
