在 bash 手册页中：

当shell非交互式时，别名不会扩展，除非 expand_aliases shell选项是使用 shopt 进行设置（请参阅 SHELL BUILTIN COMMANDS 下的 shopt 的
说明

Aliases are not expanded when the shell is not interactive, unless the expand_aliases shell option is set using shopt (see the description of shopt under SHELL BUILTIN COMMANDS below).

换句话说，默认情况下，bash shell脚本中不启用别名。当您使用 bash 运行脚本时，它将失败。

In other words, aliases are not enabled in bash shell scripts by default. When you run the script with bash, it fails.

您的 sh 似乎默认为允许脚本中使用别名。当您使用 sh 运行脚本时，它将成功。

Your sh appears to default to allowing aliases in scripts. When you run the script with sh, it succeeds.

./ command.sh 之所以起作用，是因为您的shebang格式错误（您错过了＃！/ bin / bash中的！！ code>）。

./command.sh happens to work because your shebang is malformed (you're missing the ! in #!/bin/bash).