Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -g -O2 -flto=auto -ffat-lto-objects -flto=auto
-ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security
-Wall
uname output: Linux sulfur 5.15.0-58-generic #64-Ubuntu SMP Thu Jan 5 11:43:13
UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu
Bash Version: 5.1
Patch Level: 16
Release Status: release
Description:
I have `set -x` and `BASH_XTRACEFD=1` set in a simple script that I
have in
a cron job. I'd like to see the progress of the script when run
manually,
hence `set -x`, but I want the output to go to stdout rather than
stderr so
that cron emails me only when there is an actual failure. With this
configuration, the `read` command is erroneously reading the "+" prompt
output from `set -x` into the variable. It seems like stdout is not
getting
flushed propertly.
Repeat-By:
The following script attempts to read the first column of data, line by
line, into a variable called `$var`. With `BASH_XTRACEFD` unset, it
propertly prints r1c1, r2c1, r3c1, r4c1. With `BASH_XTRACEFD=1`, `$var`
gets set to +, ++, r2c1, r3c1, r4c1. Maybe I am just being dumb?
```
#!/usr/bin/env bash
BASH_XTRACEFD=1
set -x
data=$(cat << END
r1c1 r1c2 r1c3\n
r2c1 r2c2 r2c3\n
r3c1 r3c2 r3c3\n
r4c1 r4c2 r4c3
END
)
echo -e $data | while read -r var junk; do
echo "var = $var"
done
```