与输出重定向一起使用时，shell 脚本不会解释通配符

Question

假设我有两个脚本：

• 脚本1.sh：

  #!/bin/bash
  version=2.6
  log_file="$HOME/log-file-version-$version.log"
  
  touch $log_file &>/dev/null
  
  echo "log to my log file from script 1" >> $HOME/log-file-version-?.?.log
  
  gnome-terminal --tab --active --title="script2" --  sh script2.sh
  

• 脚本2.sh：

  #!/bin/bash
  
  echo "log to my log file from script 2" >> $HOME/log-file-version-?.?.log
  

我跑script1.sh。

我家中有两个日志文件：

log-file-version-2.6.log
log-file-version-?.?.log

log-file-version-2.6.log 包含：

从脚本 1 登录到我的日志文件

log-file-version-?.?.log 包含：

log to my log file from script 2

which means that in script 1 the wildcards from line 7 (>> $HOME/log-file-version-?.?.log) were correctly interpreted, but when a script is run with sh these wildcards don't work.

Why is that and how can I fix this?

I need to use wildcards because I don't want to be passing arguments from shell script to shell script and I want them to be self-sufficient.

I'm using Ubuntu and running these scripts from the default terminal which is gnome-terminal.

Answer 1

The bash manual has this to say in the 3.6 Redirections section:

The word following the redirection operator in the following descriptions, unless otherwise noted, is subjected to brace expansion, tilde expansion, parameter expansion, command substitution, arithmetic expansion, quote removal, filename expansion, and word splitting. If it expands to more than one word, Bash reports an error.

sh does not do that: from the POSIX shell specification

如果重定向运算符是“ <<”或“ <<-”，[...]。对于其他重定向操作符，跟在重定向操作符后面的单词应进行波浪号扩展、参数扩展、命令替换、算术扩展和引号删除。非交互式 shell 不得对单词执行路径名扩展；一个交互式 shell 可以执行它，但只有在扩展会导致一个单词时才会这样做。

$ dash
$ echo foo > *
$ ls
'*'  README.md  ...

$ bash
$ echo bar >> *
bash: *: ambiguous redirect