Linux – How to make the Linux tcsh prompt bold

linuxprompttcsh

Greeting all,

I am attempting to make my Linux tcsh prompt bold. However I'm failing miserably.

I know about escape codes and I can successfully make echo'ed output bold, but I can't seem to do it for my prompt.

For example, if I use the following command:

echo "\033[1m Hello \033[0m"

I correctly get an output line that has Hello and the text is bold text.

However, if I try to change my prompt using similar logic it, fails. For example, If I attempt to change the prompt using the following command:

set prompt="\033[1m NEW-PROMPT \033[0m"

I get:

^[[1m NEW-PROMPT ^[[0m

So it seems that my prompt is not being processes the same as echo lines? Any tips on what my problem could be?

Following is a trimmed down version of my environment, which may give clues as to why I might need to use some other format for the prompt.

LANG=POSIX
LC_CTYPE=en_US.UTF-8
SHELL=/bin/csh
SSH_CLIENT=127.0.0.1 49757 22
SSH_CONNECTION=127.0.0.1 49757 127.0.0.1 22
SSH_TTY=/dev/pts/4
TERM=xterm
HOSTTYPE=i586-linux
VENDOR=suse
OSTYPE=linux
MACHTYPE=i586
SHLVL=7
HOST=psbu-jrr-lnx
CSHEDIT=emacs
CPU=i686
LESS=-M -I
LESSOPEN=lessopen.sh %s
LESSCLOSE=lessclose.sh %s %s
LESS_ADVANCED_PREPROCESSOR=no
LESSKEY=/etc/lesskey.bin
PAGER=less
MORE=-sl
MINICOM=-c on
COLORTERM=1
SSH_SENDS_LOCALE=yes
CVS_RSH=ssh
WINDOWMANAGER=/usr/bin/X11/kde
ENV=/etc/bash.bashrc
CSHRCREAD=true
LS_COLORS=no=00:fi=00:di=01;34:ln=00;36:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=41;33;01:ex=00;32:*.cmd=00;32:*.exe=01;32:*.com=01;32:*.bat=01;32:*.btm=01;32:*.dll=01;32:*.tar=00;31:*.tbz=00;31:*.tgz=00;31:*.rpm=00;31:*.deb=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.zoo=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.tb2=00;31:*.tz2=00;31:*.tbz2=00;31:*.avi=01;35:*.bmp=01;35:*.fli=01;35:*.gif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mng=01;35:*.mov=01;35:*.mpg=01;35:*.pcx=01;35:*.pbm=01;35:*.pgm=01;35:*.png=01;35:*.ppm=01;35:*.tga=01;35:*.tif=01;35:*.xbm=01;35:*.xpm=01;35:*.dl=01;35:*.gl=01;35:*.wmv=01;35:*.aiff=00;32:*.au=00;32:*.mid=00;32:*.mp3=00;32:*.ogg=00;32:*.voc=00;32:*.wav=00;32:
LS_OPTIONS=-N --color=tty -T 0
FULLENV=false
VISUAL=vi
SSH_AUTH_SOCK=/tmp/ssh-lkJkR5043/agent.5043
SSH_AGENT_PID=5044
WINDOWID=60817426
XTERM_VERSION=XTerm(208)
XTERM_SHELL=/bin/csh

Best Answer

The echo built-in performs backslash expansion on your system (this is configurable, and the default is system-dependent). The prompt variable contains the literal backslashes, and prompt expansion is a little weird.

If you want to include terminal escape sequences in your prompt, they need to be between %{…%}, as in

set prompt="%{\e[1m%}NEW-PROMPT%{\e[0m%}"

But it's simpler (and in principle more portable) to use the built-in escape sequence for bold text.

set prompt="%BNEW-PROMPT%b"
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