![]() ![]() And terminfo even allows one to write a terminal definition relative to another - notably referencing another to use as a base reference, and then adding/removing/changing the defined capabilities relative to that.Īnd. or even want to add a different definition to get somewhat different behavior out of the terminal, one can write the relevant (typically terminfo) entry for such terminal (emulation). So, if you've got a terminal (or emulation) that's not supported, and you want to add it. *nix even has the capability to write descriptions for new/different terminal types. regardless of what terminal type is being used. got a non-ANSI terminal? Use tput/terminfo/etc., and it'll still work - at least if it can and has the relevant capabilities. But again, don't presume the terminal is ANSI capable. Heck, you can even use tput to figure out ANSI escape codes if you want/need to. Presuming the terminal is ANSII or the like is a bad idea - it may not be at all.Īppropriate approach is to use the relevant terminfo libraries (or alternatively termcap - notably for older systems that may lack terminfo).Īnd as for CLI, that can generally be done using the tput utility. *nix uses and supports hundreds - if not thousands of types of terminal types (and emulations). Well, I see the tag "Linux" on the post, so I would say, in the land of *nix, that's NOT THE WAY TO DO IT! I only have three small features not in ctlseqs, and use XTVERSION and DECRQM to ensure they are only used when the terminal claims support. I do try to stick as close to stock xterm as I can. ![]() Rinse and repeat for any additional options. DECSDM was flat out documented wrong in VT340, which xterm implemented wrong, we all copied, and then j4james found other terminals doing it right, plus the Thai language manual and the VT340 tests so that was a few months of the terminal emulators updating to be correct. someone puts a mostly-transparent image up. hackerb9 recently (and I think saitoha too several years ago) bought a real VT340 and has been testing it with sequences and screenshots so that we can see what should really happen when e.g. ) there is still a lot of wiggle room as to what that means. Thing is even we had terminfo's for "yes, this terminal has sixel" (or iTerm2, or Kitty, or synchronized output, or proper DECSDM. Finally, we compare the normal and escaped version to determine whether we need to escape this character and output the result if we do.I'm quite far outside robust solutions these days. After that, with the help of the %q format modifier, we get an escaped version of the character. Next, this value is reused in printf with a prefix to get the resulting character. For each, it uses printf to extract and compare each character with its escaped form.įirst, %o returns the octal form of the character’s code. The snippet above goes through the first 128 characters in the ASCII table. The characters we would need to escape in that instance are in the output of the following script: $ for code in " Recall our discussion of writing strings without quotes. The standard built-in printf (Print Function) command also has its own special character. Let’s now explore how Bash treats sequences without any quotes. This simply means that we can spread a string over several lines without adding newline characters to it: $ text="a \ disabling history expansion via set +o histexpandįinally, the combination is ignored and removed from double-quoted strings.enclosing it in single quotes to escape an.using it at the end of a string or before whitespace characters.prefixing it with a backslash (which remains, same as with a normal character like ).Importantly, the is an exceptional character, the special meaning of which can be ignored by: ~, when beginning a string, to avoid tilde expansion and confusion with the $HOME directoryįurthermore, the prefix is not stored in the string when preceding all but one () of the characters above: $ text="!event".!, when history expansion is enabled outside POSIX mode, usually the case.\, when prefixing a character in this list except. ![]() newline, which is equivalent to under Linux.”, when we need a double quote within double quotes. ![]() `, also known as the backquote operator.These are all special characters, which may have to be escaped to preserve their literal meaning within double quotes: ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |