使用sed对文件进行操作
一.附加文本使用a\在指定行后面附加1行或多行；若不指定放置的位置，则默认放到每一行的后面。附加文本时，不允许指定范围，只允许一个地址模式。附加格式：[address] a\text\text\...text注意：1.a\通知sed对a\后面的内容进行附加操作。2.每行后面都有"\"，当sed执行到\时，将创建一个新行，并将内容添加进去。3.最后一行不能有"\"。例子：如果将附加的第一行最后的"\"去掉，那么运行脚本将会报错。pg append.sed#!bin/sed -f# append text/company/ a\Then suddenly it happened._yeeXun.执行之后：sed -f append.sed quote.txtsed: Unrecognized command: _yeeXun.修改之后pg append.sed#!bin/sed -f# append text/company/ a\Then suddenly it happened.\_yeeXun.执行脚本：sed -f append.sed quote.txtThe honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.Then suddenly it happened._yeeXun.Too bad the disco floor fell through at 23:10.The local nurse Miss P.Neave was in attendance.因为sed不与原文件打交道，编辑的只是其一个拷贝，所以我们附加的数据不会写到文件中；当执行上面的命令之后，我们查看下quote.txt文件：pg quote.txtThe honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.Too bad the disco floor fell through at 23:10.The local nurse Miss P.Neave was in attendance.二.修改文本使用c\修改指定行，格式：[address[,address]] c\text\text\...textaddress：行位置，可以使用正则表达式定位，也可以直接指定行号。text：为替换的文本，注意最后一行没有"\"。例子替换第三行数据：pg change.sed# change date/bad/ c\[Two good.]\next goods.运行脚本：sed -f change.sed quote.txtThe honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.[Two good.]next goods.The local nurse Miss P.Neave was in attendance.三.添加文本在指定行前面添加数据。[address] i\text\text\...textaddress：行位置，可以使用正则表达式定位，也可以直接指定行号。text：为替换的文本，注意最后一行没有"\"。例如：pg insert.sed# insert data/.*ing/ i\[the insert date].运行脚本：sed -f insert.sed quote.txtThe honeysuckle band played all night long for noly $90.[the insert date].It was an evening of splendid music and company.Too bad the disco floor fell through at 23:10.The local nurse Miss P.Neave was in attendance.四.删除文本删除文件中的内容，删除1行或者连续的多行，或者匹配某个模式的所有行格式：[address[,address]] d文件信息：pg quote.txtThe honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.Too bad the disco floor fell through at 23:10.The local nurse Miss P.Neave was in attendance.删除第一行：sed '1d' quote.txtIt was an evening of splendid music and company.Too bad the disco floor fell through at 23:10.The local nurse Miss P.Neave was in attendance.删除第一到第三行：sed '1,3d' quote.txtThe local nurse Miss P.Neave was in attendance.删除最后一行：sed '$d' quote.txtThe honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.Too bad the disco floor fell through at 23:10.使用正则表达式删除符合条件的所有行。删除包含以字母a开头，以字母d结尾，总长为3的行，符合的有第一行（band），第二行（and）。sed '/a.d/d' quote.txtToo bad the disco floor fell through at 23:10.The local nurse Miss P.Neave was in attendance.五.替换文本，格式：[address[,address]] s/pattern-to-find/replacement-pattern/[g p w n]address：可选项g：默认情况下，只替换首次出现模式，使用g替换全部所有出现的模式；p：默认sed将所有被替换行写入标准输出，加p将使-n选项无效；-n不打印输出结果。w：文件名，使用此选项将输出定向到一个文件。将小写的floor替换为大写的FLOOR：sed 's/floor/FLOOR/' quote.txtThe honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.Too bad the disco FLOOR fell through at 23:10.The local nurse Miss P.Neave was in attendance.将包含"$"符号的行$符号删除掉：包含$符号的行：sed -n '/$.*/p' quote.txtThe honeysuckle band played all night long for noly $90.删除$(使用空替代)符号后的行：sed -n 's/\$//p' quote.txtThe honeysuckle band played all night long for noly 90.将首次出现的"The"单词替换为"THE"，并输出到另一个文件中若sed.out存在则向里面写数据，所不存在则创建此文件并写数据：sed 's/The/THE/w sed.out' quote.txtTHE honeysuckle band played all night long for noly $90.It was an evening of splendid music and company.Too bad the disco floor fell through at 23:10.THE local nurse Miss P.Neave was in attendance.查看文件sed.out：pg sed.outTHE honeysuckle band played all night long for noly $90.THE local nurse Miss P.Neave was in attendance.--the end--
