content
macname@localhost Desktop % macname@localhost Desktop % cat ddd This is a test of the test script. This is the second test of the test script. macname@localhost Desktop %
#在行中替換文本
macname@localhost Desktop % sed 's/test/trial/' ddd This is a trial of the test script. This is the second trial of the test script. macname@localhost Desktop %
#指定sed編輯器用新文本替換第幾處模式匹配的地方
macname@localhost Desktop % macname@localhost Desktop % sed 's/test/trial/2' ddd This is a test of the trial script. This is the second test of the trial script. macname@localhost Desktop %
將替換標記指定為2的結果就是:sed編輯器只替換每行中第二次出現的匹配模式。
g替換標 記使你能替換文本中匹配模式所匹配的每處地方
macname@localhost Desktop % macname@localhost Desktop % sed 's/test/trial/g' ddd This is a trial of the trial script. This is the second trial of the trial script. macname@localhost Desktop %
p替換標記會打印與替換命令中指定的模式匹配的行。這通常會和sed的-n選項一起使用。
-n選項將禁止sed編輯器輸出。但p替換標記會輸出修改過的行。將二者配合使用的效果就是 只輸出被替換命令修改過的行
macname@localhost Desktop % cat ddd This is a test of the test script. This is the second test of the test script. Dededede Hahahahhahahaah macname@localhost Desktop % macname@localhost Desktop % sed -n 's/test/trial/p' ddd This is a trial of the test script. This is the second trial of the test script. macname@localhost Desktop %
w替換標記會產生同樣的輸出，不過會將輸出保存到指定文件中
macname@localhost Desktop % cat ddd This is a test of the test script. This is the second test of the test script. Dededede Hahahahhahahaah macname@localhost Desktop % sed 's/test/trial/w test.txt' ddd This is a trial of the test script. This is the second trial of the test script. Dededede Hahahahhahahaah macname@localhost Desktop % cat test.txt This is a trial of the test script. This is the second trial of the test script. macname@localhost Desktop %
sed編輯器允許選擇其他字符來作為替換命令中的字符串分隔符,這里感嘆號被用作字符串分隔符
macname@localhost Desktop % cat ddd This is a test of the test script. This is the second test of the test script. Dededede Hahahahhahahaah macname@localhost Desktop % macname@localhost Desktop % sed -n 's!test!trial!p' ddd This is a trial of the test script. This is the second trial of the test script. macname@localhost Desktop %
在這個例子中，感嘆號被用作字符串分隔符，這樣路徑名就更容易閱讀和理解了。
macname@localhost Desktop % macname@localhost Desktop % sed 's!/bin/bash!/bin/csh!' /etc/passwd