Gfilui

My terminal was slow.

Every time after finishing the process like:

• Installing software or sudo apt update etc...

I should wait for the shell for about 5-10 sec to type next commands.

So i searched to fix this problem.

I found one:

Add: set -x in the first of the .profile and .bashrc and set +x in the last line of that file again(.profile and .bashrc), then run bash --login in terminal.

The problem fixed and everything works perfect...
But after rebooting now i see unknown characters in terminal every-time when i press CTRL+ALT+T:

So i should type clear to have normal terminal like before!

What are these!? And how can i clear them from the terminal without slow down from the terminals speed!?

My .bashrc:

# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
set -x
case $- in
 *i*) ;;
 *) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "$debian_chroot:-" ] && [ -r /etc/debian_chroot ]; then
 debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
 xterm-color|*-256color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
 if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
 # We have color support; assume it's compliant with Ecma-48
 # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
 # a case would tend to support setf rather than setaf.)
 color_prompt=yes
 else
 color_prompt=
 fi
fi

if [ "$color_prompt" = yes ]; then
 PS1='$debian_chroot:+($debian_chroot)[33[01;32m]u@h[33[00m]:[33[01;34m]w[33[00m]$ '
else
 PS1='$debian_chroot:+($debian_chroot)u@h:w$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
 PS1="[e]0;$debian_chroot:+($debian_chroot)u@h: wa]$PS1"
 ;;
*)
 ;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
 test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
 alias ls='ls --color=auto'
 #alias dir='dir --color=auto'
 #alias vdir='vdir --color=auto'

 alias grep='grep --color=auto'
 alias fgrep='fgrep --color=auto'
 alias egrep='egrep --color=auto'
fi

# colored GCC warnings and errors
#export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'

# some more ls aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# Add an "alert" alias for long running commands. Use like so:
# sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '''s/^s*[0-9]+s*//;s/[;&|]s*alert$//''')"'

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
 . ~/.bash_aliases
fi

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if ! shopt -oq posix; then
 if [ -f /usr/share/bash-completion/bash_completion ]; then
 . /usr/share/bash-completion/bash_completion
 elif [ -f /etc/bash_completion ]; then
 . /etc/bash_completion
 fi
fi
set +x

My .profile:

# ~/.profile: executed by the command interpreter for login shells.
# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login
# exists.
# see /usr/share/doc/bash/examples/startup-files for examples.
# the files are located in the bash-doc package.

# the default umask is set in /etc/profile; for setting the umask
# for ssh logins, install and configure the libpam-umask package.
#umask 022

# if running bash
set -x
if [ -n "$BASH_VERSION" ]; then
 # include .bashrc if it exists
 if [ -f "$HOME/.bashrc" ]; then
 . "$HOME/.bashrc"
 fi
fi

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
 PATH="$HOME/bin:$PATH"
fi
set +x

What you see is the effect of set -x as explained in man bash:

-x After expanding each simple command, for command, case
command, select command, or arithmetic for command,
display the expanded value of PS4, followed by the
command and its expanded arguments or associated word
list.

As the commands in your ~/.bashrc are executed when you open a terminal and to this time apparently set -x is set, you get all its output in your fresh terminal. To disable it, just remove all the set -x and set +x line you introduced.