ECHO

• Parameter
• -n : 不要在最後自動換行
• -e : 若字串中出現以下字元, 則特別加已處理, 而不將之當成一般文字輸出.
• \a : 發出警告聲
• \n : 刪除前一個字元
• \c : 最後不加上換行符號
• \f : 換行且游標停留在原來位置
• \n : 換行且游標移至行首
• \r : 游標移至行首, 但不換行
• \t : 插入 tab
• \v : 與 \f 相同
• \\ : 插入 \ 字元
• \nnn : 插入 nnn (八進位) 所代表的 ASCII字元

Example



原有文件: test.file
文件內容:

• this is line 1 on original test.file!
• this is line 2 on original test.file!!
• this is line 3 on original test.file!!!

• 文件已有文字, 新增一行在文件最後.
• # echo "add one more line" >> test.file
• # cat test.file
• this is line 1 on original test.file!
• this is line 2 on original test.file!!
• this is line 3 on original test.file!!!
• add one more line

• 新增兩行指令在script file最後面.
• # echo -e "sleep 2\n./mnt/usb/sample_uarttest" >> test.sh
• # cat test.sh
• this is line 1 on original test.file!
• this is line 2 on original test.file!!
• this is line 3 on original test.file!!!
• sleep 2
• ./mnt/usb/sample_uarttest

• 新增 tmp.file 的內容至 test.file 後面.
• tmp.file content:
• there is line A on tmp.file~
• there is line B on tmp.file~~
• there is line C on tmp.file~~~

• # cat tmp.file >> test.file
• # cat test.file
• this is line 1 on original test.file!
• this is line 2 on original test.file!!
• this is line 3 on original test.file!!!
• 
  
• there is line A on tmp.file~
• there is line B on tmp.file~~
• there is line C on tmp.file~~~

• 在 test.file 內容和 tmp.file 內容中間加入一行 Hello World!!!
• # echo "Hello World!!!" | cat - tmp.file >> test.file
• # cat test.file
• this is line 1 on original test.file!
• this is line 2 on original test.file!!
• this is line 3 on original test.file!!!
• Hello World!!!
• there is line A on tmp.file~
• there is line B on tmp.file~~
• there is line C on tmp.file~~~