writefile

问题 I'm designing a system that will write time series data to a file. The data is blocks of 8 bytes divided into two 4 bytes parts, time and payload. According to MSDN the WriteFile function is atomic ( http://msdn.microsoft.com/en-us/library/aa365747(VS.85).aspx ), if the data written is less than a sector in size. Since the file will only contain these blocks (there is no "structure" of the file so it's not possible to reconstruct a damaged file), added one after each other, it's vital that

问题 I'm designing a system that will write time series data to a file. The data is blocks of 8 bytes divided into two 4 bytes parts, time and payload. According to MSDN the WriteFile function is atomic ( http://msdn.microsoft.com/en-us/library/aa365747(VS.85).aspx ), if the data written is less than a sector in size. Since the file will only contain these blocks (there is no "structure" of the file so it's not possible to reconstruct a damaged file), added one after each other, it's vital that

问题 I'm designing a system that will write time series data to a file. The data is blocks of 8 bytes divided into two 4 bytes parts, time and payload. According to MSDN the WriteFile function is atomic ( http://msdn.microsoft.com/en-us/library/aa365747(VS.85).aspx ), if the data written is less than a sector in size. Since the file will only contain these blocks (there is no "structure" of the file so it's not possible to reconstruct a damaged file), added one after each other, it's vital that

问题 So I have a vector which has three numbers. 65, 66, and 67. I am converting these numbers from int to binary and appending them in a string. the string becomes 100000110000101000011 (65, 66, 67 respectively). I am writing this data into a file through dynamic_bitset library. I have BitOperations class which does the reading and writing into file work. When I read the data from file instead of giving the above bits it gives me these 001100010100001000001 bits. Here is my BitOperations class:

问题 I am trying to simply replace a line in a text file using JavaScript. The idea is: var oldLine = 'This is the old line'; var newLine = 'This new line replaces the old line'; Now i want to specify a file, find the oldLine and replace it with the newLine and save it. Anyone who can help me here? 回答1: This should do it var fs = require('fs') fs.readFile(someFile, 'utf8', function (err,data) { var formatted = data.replace(/This is the old line/g, 'This new line replaces the old line'); fs

问题 I am trying to simply replace a line in a text file using JavaScript. The idea is: var oldLine = 'This is the old line'; var newLine = 'This new line replaces the old line'; Now i want to specify a file, find the oldLine and replace it with the newLine and save it. Anyone who can help me here? 回答1: This should do it var fs = require('fs') fs.readFile(someFile, 'utf8', function (err,data) { var formatted = data.replace(/This is the old line/g, 'This new line replaces the old line'); fs

问题 I am trying to simply replace a line in a text file using JavaScript. The idea is: var oldLine = 'This is the old line'; var newLine = 'This new line replaces the old line'; Now i want to specify a file, find the oldLine and replace it with the newLine and save it. Anyone who can help me here? 回答1: This should do it var fs = require('fs') fs.readFile(someFile, 'utf8', function (err,data) { var formatted = data.replace(/This is the old line/g, 'This new line replaces the old line'); fs

问题 i am reading a value from a file and then adding up with another and then writing back to the same file. total = 0 initial = 10 with open('file.txt', 'rb') as inp, open('file.txt', 'wb') as outp: content = inp.read() try: total = int(content) + int(initial) outp.write(str(total)) except ValueError: print('{} is not a number!'.format(content)) it is successfully reading the value from file, but when writing, nothing is stored in the file. what is wrong here? update I want to replace the old

问题 I've got a simple web-page that generates a CSV file that I want the user to be able to download once its creation is complete. Here's a summary of my situation: The CSV file can be created in-memory or on disk. Doesn't matter to me. Once I'm done transmitting the CSV file, I do not want it to continue residing on disk. I've tried various code using Response.WriteFile, .TransmitFile, .BinaryWrite and .Write, but to no avail. When I say "to no avail" , I mean that rather than the CSV file

问题 How can I write contents of a CString instance to a file opened by CreateFile using WriteFile Win32 API function? Please note MFC is not used, and CString is used by including "atlstr.h" edit: Can just I do WriteFile(handle, cstr, cstr.GetLength(), &dwWritten, NULL); or WriteFile(handle, cstr, cstr.GetLength() * sizeof(TCHAR), &dwWritten, NULL); ? 回答1: With ATL it's like this: CString sValue; CStringW sValueW(sValue); // NOTE: CT2CW() can be used instead CAtlFile File; ATLENSURE_SUCCEEDED