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- def writeToFile(self, txt, pgno, offset):
- n = 1024
- # Customize file open location for your own self
- fopen = open("F:/labOS/funner.dat", "r+")
- # moves the pointer of file towards the page number specified, as each page consists of 1024 bytes to it is multiplied by 1024
- # the product is then added with offset to start writing to the file from the offset specified
- fopen.seek(pgno*1024 + offset)
- # if file exists then open
- if fopen:
- fopen.seek(pgno*1024+offset)
- # checks whether sum of offset and len(txt) is greater than 1024 means that it actually checks whether the data inputed
- # by the user is greater than 1024 bytes.
- # for example: the word "Hassan" contains 6 letters hence it contains 6 Bytes so it will false the following condition
- if offset + len(txt) > 1024:
- buffer = txt
- # writes to file to the buffer array from 0 index to the difference of 1024 and offset
- fopen.write(buffer[0:(1024 - offset)])
- self.mainPage[pgno] = True
- # loops till 1024 - size of Byte
- for i in range(n):
- # initialized tmppg no to the respective mainPage
- tmppgno = self.mainPage[i]
- # moves the pointer as of Byte size
- fopen.seek(tmppgno*1024)
- # Writes to the file by slicing such that it starts writing from difference of 1024-offset+1 and ends at the
- # position returned by the difference of len(txt) and 1024-offset
- fopen.write(buffer[1024-offset+1: len(txt) - (1024-offset)])
- self.pgoffset[i] = len(txt) - (1024-offset)
-
- self.mainPage[i] = True
- # else if the length of text entered by the user is less than 1024
- else:
- fopen.seek(pgno*1024+offset)
- buffer = txt
- fopen.write(buffer[0:len(txt)])
- self.pgoffset[pgno] = len(txt) +offset
- fopen.close()
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