mac OS X下的sed出錯
其實這裏只是記錄一下自己在用sed修改文件的時候遇到的現象。
網上有很多sed的講解，還算詳細。今天打算改一些網頁，打算加一句代碼，於是有了如下的語句：
sed -i "s/class=\"look\"/class=\"look\" id=\"lookBigView\"/g" *然而報錯：
sed: -i may not be used with stdin = 。=|||
我覺得自己循規蹈矩，按照步驟一點點來的，什麼叫不能用標準輸入……我沒有用啊！！！然後利用國內某知名搜索引擎一下午……無解……面對這樣的腳本問題，一句話的事情，作爲一名有志氣的程序員，怎能咽得下這口氣！於是轉戰Google，好吧，瞬間把我拽到的Stackoverflow（原問題點我）
The problem is that Mac OS X uses the BSD version of sed, which treats the -i option slightly differently. The GNU version used in Linux takes an optional argument with -i: if present, sed makes a backup file whose name consists of the input file plus the argument. Without an argument, sed simply modifies the input file without saving a backup of the original.
In BSD sed, the argument to -i is required. To avoid making a backup, you need to provide a zero-length argument, e.g. sed -i ” y.tab.c ….
Your command, which simply edits y.tab.c with no backup in Linux, would attempt to save a backup file using ‘y.tab.c’ as an extension. But now, with no other file in the command line, sed thinks you want to edit standard input in-place, something that is not allowed.
終於明白不是我的錯了(T 0 T)…Mac OS X是BSD的孩子，那麼就跟着父親來，sed -i 之後需要加參數，表示備份原文件……
於是，代碼如下即可：
sed -i "" "s/class=\"look\"/class=\"look\" id=\"lookBigView\"/g" *