bash-prompt | Improved bash prompt with support for Git | Script Programming library

Why bash color encoding doesn't need terminating character?

It needs one and has one - the terminating character is m.

why doesn't it need a terminating character such as ]

Because a character, in this case character m, is used to detect the end of ansi escape sequence.

For more information read wikipedia ansi escape code and ECMA-35 around section 13 and ECMA-48 section 5.

I read ] is required to terminate the escape sequence

The \[ and \] are used to notify bash that a prompt it uses has an ansi escape sequence inside if it, so that when bash calculates the length of line with the prompt it doesn't make mistakes.

It's used like:

As mentioned in a comment, you should use read's -p option to print the prompt, rather than trying to set it up before the read command.

The -e option asks read to use the readline library to handle the input, allowing a wider range of line-editing characters. However, in order to implement these behaviours, readline needs to be able to redraw the current line, and that's not possible if there is anything on the current line when the read starts. It's not possible because Unix provides no mechanism for an application to look at what's being displayed on the console. So under some circumstances, readline will simply clear the line. Using the -p option allows readline to output the prompt, and it can then know what the line currently looks like.

Try this:

To narrowly answer the question, spawning three process substitutions and concatenating their results will let the work happen in parallel, while generating output in a known order:

Moving the trap to after PS1 is set eliminated the problem. I don't know why that makes a difference.

Please try to add the below lines in your git config file and then restart the command prompt and run git commands.

Bash has always had trouble handling long prompts with invisible characters, so the usual practice is to avoid them. For example, you could automatically trim the length of the prompt by omitting the beginning of the path if it is too long, or you could automatically output a trailing newline if the path is very long. (In such cases, you might want to use $COLUMNS, which will normally tell you the width of the window.)

In patch 19 to bash v4.4 (which I realise is not really relevant to your environment since you seem to still be using the antique version of bash provided by a default OS X install), a long-standing bug was corrected, which had the effect of triggering a segfault in certain very rare cases of multiline prompts with both invisible and multibyte characters. The behaviour definitely changed between v4.4.18 and v4.4.19, but even with that patch very long prompts cause problems when the prompt extends to a third line.

There is a comment in lib/readline/display.c which indicates that the readline library assumes that prompts will not exceed two lines. I suggest that you use that as a limit.

It seems you are trying to read the list of all file/folder names in a particular directory. In your case the current working directory. It also appears you are interested in a *NIX solution since you tried to use ls.

There are many ways to read the output from a subprocess into the parent process. You can use fork/exec with pipes or you are use popen.

But for this example you need not go through ls. You are directly read the directory using the Linux API.

You need to use the functions opendir and readdir.

Consider the following program -

The answer was to scrap this whole idea and use a better one..

Lets step back first.. Big Picture:
Goal was to make the script program output an executable shell script of the entire recorded session.

Back to Answers..
The above implementation was supposed to remove all prompts and control characters from the output of script (which is the input examples I gave) and then remove the output of each command (i.e. any line that didn't contain control characters).
Passing the evalPS function to perl to execute proved to be quite redundant and getting bash and perl to expand the parameters correctly was a nightmare..

The Final Solution
Scrapped the perl regex idea and used a combination of subshell and history redirection to grab the commands for the entire script session, while it was running.

The entire implementation looks like this: