[pbs-devel] [PATCH proxmox] cli/text_table: calculate correct column width for unicode characters

[Dominik Csapak <d.csapak@proxmox.com>]

When printing unicode text, a glyph can take up more (or less) space than
a single column. To handle that, use the 'unicode-width' crate which
calculates the width by the unicode standard.

This makes the text tables correctly aligned when printing unicode
characters (e.g. in a datastore/user/syncjob comment).

'unicode-width' is used itself in the rust compiler to format errors
(see e.g. the Cargo.toml in /compiler/rustc_errors of the rust git)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
not strictly necessary, but was easy enough to do, makes printing with unicode
characters nicer and only needs one dependency which must be available anyway...

 proxmox/Cargo.toml                | 1 +
 proxmox/src/api/cli/text_table.rs | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/proxmox/Cargo.toml b/proxmox/Cargo.toml
index b901969..73da51c 100644
--- a/proxmox/Cargo.toml
+++ b/proxmox/Cargo.toml
@@ -17,6 +17,7 @@ anyhow = "1.0"
 lazy_static = "1.4"
 libc = "0.2"
 nix = "0.19.1"
+unicode-width ="0.1.8"
 
 # tools module:
 base32 = { version = "0.4", optional = true }
diff --git a/proxmox/src/api/cli/text_table.rs b/proxmox/src/api/cli/text_table.rs
index 84d9f34..d136629 100644
--- a/proxmox/src/api/cli/text_table.rs
+++ b/proxmox/src/api/cli/text_table.rs
@@ -2,6 +2,7 @@ use std::io::Write;
 
 use anyhow::*;
 use serde_json::Value;
+use unicode_width::UnicodeWidthStr;
 
 use crate::api::schema::*;
 
@@ -472,7 +473,7 @@ fn format_table<W: Write>(
             let lines: Vec<String> = text
                 .lines()
                 .map(|line| {
-                    let width = line.chars().count();
+                    let width = UnicodeWidthStr::width(line);
                     if width > max_width {
                         max_width = width;
                     }
@@ -564,10 +565,11 @@ fn render_table<W: Write>(
                     text.push(' ');
                 }
 
+                let padding = column.width - UnicodeWidthStr::width(line.as_str());
                 if column.right_align {
-                    text.push_str(&format!("{:>width$}", line, width = column.width));
+                    text.push_str(&format!("{:>width$}{}", "", line, width = padding));
                 } else {
-                    text.push_str(&format!("{:<width$}", line, width = column.width));
+                    text.push_str(&format!("{}{:<width$}", line, "", width = padding));
                 }
 
                 if !options.noborder {
-- 
2.30.2