hexdump:tldr:6568e

The hexdump command is a utility in Unix-like operating systems used to display the hexadecimal and ASCII representation of a given file or input.

In the command hexdump -C ${filename}, the ${filename} is a placeholder for a variable that should be replaced with the actual name of a file you want to examine.

When you run this command in a terminal or command prompt, it will display the contents of the specified file in a format that includes both the hexadecimal values and their corresponding ASCII representation. The -C option is used to display the output in a canonical format with ASCII characters displayed on the right side.

For example, if you have a file called "example.txt" and you run the command hexdump -C example.txt, it will show you the hexadecimal and ASCII representation of the file's contents.

The output of the hexdump -C command typically looks something like this:

00000000  48 65 78 61 64 65 63 69  6d 61 6c 20 76 61 6c 75  |Hexadecimal valu|
00000010  65 73 20 69 6e 20 74 65  78 74 20 66 6f 72 6d 61  |es in text forma|
00000020  74 00 0a 5a 7a 79 78 20  69 73 20 61 77 65 73 6f  |t..Zzyx is aweso|
...

This output represents the file in both hexadecimal and ASCII. Each line starts with a memory address (in hexadecimal) followed by the corresponding hexadecimal values of the file contents and then the ASCII representation on the right.