Updating string in place on terminal

Zariel · 2010-02-13 18:15:43

Hi, I want to do a couple of things, for starters im trying to print an updating string to the terminal, like how powerpill does it when you have the download complete messages and the speed updating at the bottom, how can I achieve this in python? Ive managed to get the stdout from aria2c.

Bralkein · 2010-02-14 00:34:30

I know one way, but I suspect it's probably not the preferred method. Still, it seems to work:

#!/usr/bin/env python
import time
import sys

for i in range (1,5):
  sys.stdout.write("%d\r" % (i,))
  sys.stdout.flush()
  time.sleep(1)
print "\n",

sys.stdout.write("First message")
sys.stdout.flush()
time.sleep(1)
sys.stdout.write("\rupdated*")
sys.stdout.flush()
print "\n",

If you run the code it should be obvious how it works. I'm sure you're clever enough to generalise it into a nice simple method. Anyway, it seems a bit crummy if you ask me but it might work if nobody comes up with a better idea. Maybe you could use ncurses but that might be a bit of overkill for your purposes, I don't know.

PirateJonno · 2010-02-14 00:37:38

http://www.tldp.org/HOWTO/Bash-Prompt-HOWTO/x361.html

brisbin33 · 2010-02-14 01:06:30

you could also take a look at /etc/rc.d/functions, those nice [BUSY] > [DONE] > [FAIL] messages are in bash using a derivation of PirateJonno's link i'd imagine.

fsckd · 2010-02-15 00:21:48

I don't know about python, but in bash you should use tput. 'Cause different terminals are different.

tavianator · 2010-02-15 07:31:27

http://docs.python.org/dev/howto/curses.html

Or, likely more convenient, man console_codes.

Profjim · 2010-02-15 21:07:50

Okay, I don't have time to pretty this up too much, but I have it in my scrap folder. Compiled it a while ago by trial and error.

You'd use these like this:

printf "%s%s%s" $'\eSOMERAWCONTROLCHARS' "text" $'\eSOMEMORE'

or if `tput foo` produces \eSOMERAWCONTROLCHARS and `tput bar 5` produces \eSOMEMORE, then you could use:

printf "%s%s%s" "$(tput foo)" "text" "$(tput bar)"

You could use `echo -e ...` instead of printf if you like.

The raw codes given are all understood by urxvt. (Some depend on compile-time options being enabled, I compile urxvt myself so I haven't kept close track of which options are enabled in the default Arch install. Most of the ones needed below should be.)

Many of these will also work on other terminals.

TPUT CAPABILITIES and RAW TERMCODES

tput clear # same as "clear"
tpur rs1 # does clear and also clears scrollback buffer
         # raw version = \Ec

tput cols
tput lines
tput colors
tput btns # number of mouse buttons


tput ht # tab
tput cbt # backtab (raw is \E[Z)
other spacing chars:
    \n = ^J = \012 = \x0a
    \v = ^K = \013 = \x0b
    \f = ^L = \014 = \x0c
    \r = ^M = \015 = \x0d
tput bel # bell char (\a = ^G = \007)
tput flash # visual bell

tput sc # save cursor (sc=\E7, also \E[s, also \E[?1048h)
tput rc # restore cursor (rc=\E8, also \E[u, also \E[?1048l)

Below I use _ as an integer variable:

tput cuu _ # go up _ lines, stay in this column (cuu _=\E[_A)
tput cuu1 # same as cuu 1 (cuu1=\E[A)
not in terminfo:
    \e[_F equivalent to cuu _ \r

tput cud _: down _ lines, stay this column (cud=\E[_B)
tput cud1 (^J, it's ignored by urxvt?)
    won't go to line where no text has been written yet
    use \v or \f to do that (\eD works too)
    \n also goes down one line, then does \r (go to column 0) (\eE works too)

not in terminfo:
    \e[_E equivalent to cud _ \r (like \n or \eE)

the following means you can use "tput cuf _" (whose raw version is \E[_C) or "tput cuf1" (whose raw version is \E[C):
tput cuf1, cuf _ # right _ spaces (doesn't overwrite) (cuf=\E[_C)

tput cub1 (^H), cub _ # left _ spaces (cub=\E[_D)
tput cup RR CC # go to row,col (1-based, topleft of screen) (cup=\E[rr;ccH, \e[rr;ccf works too)
tput home (\E[H)
tput cr # goto col 1 (^M)
tput hpa _ # go to column _ (1-based) (\E[_G)
tput vpa _ # go to row _ (1-based) (\E[_d)

tput ri, rin _ # "scroll back" i.e. move up _ lines, while discarding bottom _ lines of output (even if you're not there) (ri=\EM, rin=\E[_T, rin 1 works better than ri)
tput ind (^J, it's ignored), indn _ # "scroll forward" i.e. move down _ lines, but doesn't restore lines deleted by scrolling back (indn=\E[_S)

tput ech _ #  erase ahead _ chars (overwrites with current bg color) (ech=\E[_X)
    tput el # clear to end of line, stay here (el=\E[K, also \e[0K)
    tput el1 # clear to start of line, stay here (el1=\E[1K)
        \e[2K clears whole line
    tput ed # clear to end of screen, stay here (ed=\E[J, also \e[0J)
        \e[1J clears screen before cursor
        \e[2J clears whole screen
tput ich1, ich _ # insert ahead _ chars (using current bg color) (ich,ich1=\E[_@)
tput il1, il _ # insert _ lines (scroll the line you're currently writing down _, discarding bottom _ lines of output, cursor goes to top of newly-scrolled region
                 this differs from ri/rin in that it inserts blank lines) (il,il1=\E[_L)
tput dch1, dch _ # delete ahead _ chars (dch,dch1=\E[_P)
tput dl1, dl _ # delete _ lines, including \n, stay this column (dl,dl1=\E[_M)

COLORS AND ATTRIBUTES
tput bold (\E[1m)
tput sitm/ritm   # italics (\E[3m \E[23m)
tput smul/rmul      # underline (\E[4m \E[24m)
tput blink # blinks and bold bg (\E[5m, rapid blink is 6)
tput rev, smso/rmso      # standout (\E[7m \E[27m)
    attrib 8=invis is not implemented
    attrib 2=? is not implemented
tput op # use default colors (op=\E[39;49m)
Colors:
    0 black, 1 red, 2 green, 3 yellow, 4 blue, 5 magenta, 6 cyan, 7 white, 9 default
    3_ fg, 4_ bg
    3_;1 may use bright fg, as does 9_
    49;5 and 49;6 blink
    other 4_;5 and 4_;6 use bold/bright bg, as does 10_
    38;5;_ fg to color0-255
    48;5;_ bg to color0-255
tput sgr0 # clear all attributes (sgr0=\E[m\017)

\e8 seems to restore attributes and colors as well as position
\e[?7h,\e[?7l seems to reset attributes and colors

\e[?XXYY        where YY=s to save, r to restore, h to set, l to clear, t to toggle
                and XX=5 whole terminal reverse video (used by flash)
                    XX=6 write from 0,0
                    XX=7 do wrap to next line (smam=\e[?7h, rmam=\e[?7l)
                    XX=25 cursor is visible (cnorm/cvvis=\e[?25h, civis=\e[?25l)
                    XX=47 use alternate buffer
                    XX=1047 use alternate buffer, clear when returning from it
                    XX=1048 save cursor on set, restore on clear
                    XX=1049 use alternatr buffer, clear on switching to it (smcup=\e[?1049h, rmcup=\e[r\e[?1049l)


write in "status line"/xterm title:
    tput dsl # delete it (\E]2;\007)
    tput tsl # to status line (\E]2)
    tput fsl # from status line to main window (^G)
"\e]XX;YY\e\\" sets xterm parameters, where XX;YY=
                0;text    set icon name and window title to text
                1;text    set icon name only
                2;text    set window title only
                10;color or index    change terminal fg to color
                11;color or index    change terminal bg to color
                12;color or index    change cursor fg to color
                13;color or index    change pointer fg to color
                17;color or index    change highlight to color
                706;color or index    change bold to color
                707;color or index    change underlined chars to color
                704:color or index    change italics to color
                50 or 710;font        change normal fontset
                711;font            change bold fontset
                712;font            change italics fontset
                713;font            change boldItalics fontset
                720 or 721;0        clear scrollback buffer
                777;extension:parameters    call perl extension



\eD                index (not in terminfo)

Last edited by Profjim (2010-02-15 21:22:51)

Arch Linux

#1 2010-02-13 18:15:43

Updating string in place on terminal

#2 2010-02-14 00:34:30

Re: Updating string in place on terminal

#3 2010-02-14 00:37:38

Re: Updating string in place on terminal

#4 2010-02-14 01:06:30

Re: Updating string in place on terminal

#5 2010-02-15 00:21:48

Re: Updating string in place on terminal

#6 2010-02-15 07:31:27

Re: Updating string in place on terminal

#7 2010-02-15 21:07:50

Re: Updating string in place on terminal

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