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@rene-d
Created June 14, 2023 20:50
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#!/usr/bin/env python3
"""
Read terminal properties and imgcat in Python.
References:
https://en.wikipedia.org/wiki/ANSI_escape_code
https://iterm2.com/documentation-escape-codes.html
https://iterm2.com/documentation-images.html
"""
import sys
import termios
import re
import binascii
import io
def _send_command(cmd: str) -> str:
"""
Send a command to the terminal and read the response with 200ms.
"""
old_stdin_mode = termios.tcgetattr(sys.stdin)
rep = termios.tcgetattr(sys.stdin)
rep[3] = rep[3] & ~(termios.ECHO | termios.ICANON) # lflags
rep[6][termios.VMIN] = 0 # cc, Minimum number of characters for noncanonical read (MIN).
rep[6][termios.VTIME] = 2 # cc, Timeout in deciseconds for noncanonical read (TIME).
termios.tcsetattr(sys.stdin, termios.TCSAFLUSH, rep)
try:
sys.stdout.write(cmd)
sys.stdout.flush()
return sys.stdin.read()
finally:
termios.tcsetattr(sys.stdin, termios.TCSAFLUSH, old_stdin_mode)
def name_version():
"""
Report terminal name and version.
Sequence: CSI > q
"""
cmd = "\033[>q"
rep = _send_command(cmd)
rep = re.match("\033P>\\|(.+)(\007|\033\\\\)", rep)
if rep:
return rep.group(1)
def cell_size():
"""
Report the size in points of a single character cell.
Sequence: OSC 1337 ; ReportCellSize ST
"""
cmd = "\033]1337;ReportCellSize\007"
rep = _send_command(cmd)
rep = re.match("\033\\]1337;ReportCellSize=(.*)(\007|\033\\\\)", rep)
if rep:
return rep.group(1).split(";")
def cursor_position():
"""
Device Status Report (DSR): report the cursor position (CPR)
Sequence: CSI 6n
"""
cmd = "\x1b[6n"
rep = _send_command(cmd)
rep = re.match("\033\\[(.*)R", rep)
if rep:
return rep.group(1).split(";")
def imgcat(img: bytes, name=None, width=None, height=None, preserve_aspect_ratio=True):
"""
Display an image in a capable terminal (iTerm2, WezTerm, etc.).
"""
sys.stdout.write(f"\033]1337;File=inline=1;size={len(img)}")
if name:
sys.stdout.write(f";name={binascii.b2a_base64(name.encode()).decode()}")
if width:
sys.stdout.write(f";width={width}")
if height:
sys.stdout.write(f";height={height}")
if not preserve_aspect_ratio:
sys.stdout.write(f";preserveAspectRatio=0")
sys.stdout.write(":")
sys.stdout.write(binascii.b2a_base64(img).decode())
sys.stdout.write("\007\n")
class ImgCat(io.BytesIO):
"""
Class version of the imgcat function.
Example:
from PIL import Image
im = Image.open("image.png")
im.save(imgcat.ImgCat(height=25), "PNG")
"""
def __init__(self, *args, **kwargs):
self.args = args
self.kwargs = kwargs
self.done = False
super().__init__()
def flush(self):
self.imgcat()
return super().flush()
def close(self):
self.imgcat()
return super().close()
def imgcat(self):
if self.done:
return
self.done = True
if not sys.stdout.isatty():
return
img = self.getvalue()
if len(img) > 0:
imgcat(img, *self.args, **self.kwargs)
if __name__ == "__main__":
import argparse
parser = argparse.ArgumentParser("Display an image in the terminal")
parser.add_argument("-H", "--height", metavar="N", type=str)
parser.add_argument("-W", "--width", metavar="N", type=str)
parser.add_argument("--no-preserve-aspect-ratio", action="store_true")
parser.add_argument("files", nargs="*")
args = parser.parse_args()
print(args)
for file in args.files:
imgcat(
open(file, "rb").read(),
width=args.width,
height=args.height,
preserve_aspect_ratio=not args.no_preserve_aspect_ratio,
)
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