shell命令結(jié)果重定向到文件，如果文件只讀導(dǎo)致...

螃蟹009

我們經(jīng)常在腳本中這么使用

例如:

SHLIST=`ls 2>>/var/log/test`
SHLIST=`ls 2>>/var/log`

但是假如/var/log/test是個只讀文件或者log是個目錄等等吧，各種以外情況，

會導(dǎo)致，提示說xxx文件有問題

echo $SHLIST輸出為空

請問如何規(guī)避這個問題，就是說:
無論重定向的文件是好是壞，不影響我前面命令的執(zhí)行

jason680

回復(fù) 1# 螃蟹009

SHLIST=`ls 2>>/dev/null`
   

螃蟹009

回復(fù) 2# jason680


    某些特殊情況文件有問題(有問題時候希望他不影響前面程序的執(zhí)行)，但是沒有問題時候又希望可以正常記錄

jason680

回復(fù) 3# 螃蟹009

check file before using
   
$ man bash
...

       When  used with [[, the < and > operators sort lexicographically using
       the current locale.  The test command sorts using ASCII ordering.

       -a file
              True if file exists.
       -b file
              True if file exists and is a block special file.
       -c file
              True if file exists and is a character special file.
       -d file
              True if file exists and is a directory.
       -e file
              True if file exists.
       -f file
              True if file exists and is a regular file.
       -g file
              True if file exists and is set-group-id.
       -h file
              True if file exists and is a symbolic link.
       -k file
              True if file exists and its ``sticky'' bit is set.
       -p file
              True if file exists and is a named pipe (FIFO).
       -r file
              True if file exists and is readable.
       -s file
              True if file exists and has a size greater than zero.
       -t fd  True if file descriptor fd is open and refers to a terminal.
       -u file
              True if file exists and its set-user-id bit is set.
       -w file
              True if file exists and is writable.
       -x file
              True if file exists and is executable.
       -G file
              True if file exists and is owned by the effective group id.
       -L file
              True if file exists and is a symbolic link.
       -N file
              True if file exists and has been modified  since  it  was  last
              read.
       -O file
              True if file exists and is owned by the effective user id.
       -S file
              True if file exists and is a socket.
       ...

sync_1521

試試SHLIST=`ls 2|tee -a /var/log` 不過最好還是像樓上所說的check file before using

螃蟹009

回復(fù) 5# sync_1521

這個就是我想要的，在用之前確實應(yīng)該做個檢查