In last week’s Lesson, I demonstrated the strdup() function. That function isn’t available in every C language library, but it’s easy to craft your own.
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Your Own strdup() Function
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Category Archives: Lesson
To Copy or to Duplicate a String
The C library function to copy a string is strcpy(), which (I’m guessing) stands for string copy.
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99 Bottles of Beer
This month’s Exercise involves coding the lyrics for a cumulative song. Perhaps the most famous, and certainly the most obnoxious, cumulative song is the old warhorse, 99 Bottles of Beer.
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Check That Sum
The old computer processing adage is “garbage in, garbage out.” What it means is that unless your data is good, don’t expect to see good results. So what can be done to ensure that the data is good? A checksum, that’s what.
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Encoding and Decoding, Part VII
The final part of the decoding program performs the actual decoding: A two-byte hexadecimal string is converted into a value. That value is then manipulated by the XOR 0xAA operation. The result is output. Yep, it took a long time to get to this point.
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Encoding and Decoding, Part VI
Data encoded by my hexencode system is formatted. That means that the decoding program must look for both the header and footer in that formatted output. In last week’s Lesson, code was added to confirm the input file’s first line as the header. This week’s modification is to search for the end of encoded text.
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Encoding and Decoding, Part V
You don’t want your decoding program to waste time attempting to process input that isn’t in the proper format. That’s why the encoding program bothers to put a specific header as the first line of text. Therefore, one of the first tasks for the decoding program is to check for that specific header.
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Encoding and Decoding, Part IV
It would be a grand thing to set out and craft the entire decoding program in one sitting. That’s ambition in action, but it doesn’t demonstrate much programming experience.
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Encoding and Decoding, Part III
You can output values in the hexadecimal format, thanks to the %x and %X placeholders in the printf() function. Getting hex strings as input is also possible, but not entirely obvious.
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Encoding and Decoding, Part II
To help improve the presentation of encoded data, consider sprucing up the output.
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