I'm trying to print non-printable characters in C files, but I can't print the given character because I don't know its meaning. I noticed this when I compared my program with cat.

cat -nt file.txt:

134  is 127 7f

cat -n file.txt:

134 ^? is 127 7f

CodePudding user response：

In the Caret Notation (which cat uses when -v or -t is specified) ^? represents the DEL character (Unicode U 007F, ASCII encoding 127 decimal, 0x7f in hex).