Removing non printable characters from expect logs?

Question

How can I either strip the following character sequences from my files? ^[[64;8H, ^[[?25h, ^[[1;64r etc or avoid having expect add them in the first place?

Background:

I'm using a collection of expect scripts for certain tasks.

The output files I'm collecting often contain the above type of characters (as displayed in emacs / vi / cat -v). I've tried a number of tr commands like the following but it only makes the [64;8H etc visible.

tr -dc '[:print:]\n' < input

EDIT:

The results from above on a problematic line

[1;64r[64;1H[64;1H[2K[64;1H[?25h[64;1H[64;.....

score 7 · Accepted Answer · edited Apr 13 '17 at 12:13

7

You were close. You want

tr -dc '[:print:]\n' <input

From the tr(1) man page:

-c, -C, --complement
use the complement of SET1

Update

If you want to remove escape sequences as well, you can use the following sed snippet:

sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g"

It's taken from a serverfault question called In CentOS 4.4, how can I strip escape sequences from a text file?

edited Apr 13 '17 at 12:13

Community

1

answered Dec 12 '13 at 17:15

Joseph R.

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Thanks Joseph. That makes the characters visible but doesn't strip them. I'll show the results in the question body. – Tim Brigham Dec 12 '13 at 17:16
@TimBrigham Does the update help? – Joseph R. Dec 12 '13 at 17:45

score 1 · Answer 2 · answered Dec 12 '13 at 18:03

1

After some experimentation (I use the fish shell, which colourizes everything):

perl -pe '
    s/\033\\\\\[(\d+;)*\d*[[:alpha:]]//g;
    s/\033\\\\\]0;//g;
    s/\x7//g;
    s/\033\(B//g;
' expect.log

answered Dec 12 '13 at 18:03

glenn jackman

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Removing non printable characters from expect logs?

2 Answers2