如何获取Shell脚本的输出并将其放在命令行的文件中？

如何获取Shell脚本的输出并将其放在命令行的文件中？

# write to file
sh myscript > out.txt
# append to file
sh myscript >> out.txt
# write both output and stderr to file
sh myscript 2&1>> out.txt

$ ./foo >> myoutputfile.txt