1. linux有什麼命令可以提取指定的字元串
1. 例子
提取字元串以下字元串 error: 與 : 之間的子字元串。並消除空格。
"src/network/misc/nv_net_udp.c:17:fatalerror:nv_net_tools.h:Nosuchfileordirectory"1
2. 命令
echo"src/network/misc/nv_net_udp.c:17:fatalerror:nv_net_tools.h:Nosuchfileordirectory"|sed-r's/.*error:(.*):.*/1/'|seds/[[:space:]]//g1
該命令涉及 sed 命令的』反向引用』章節, 1 代表 (.*)
3. 結果
nv_net_tools.h1
4. 拓展 ： 解決編譯錯誤
leon$makeclean&&makeallarm-hisiv100nptl-linux-gcc-c-fPIC-Wall-g-ggdb-O0-DHI3518_CHIP-DLINUX-I./src/include-I./src/include/common-I./src/include/camera-I./src/include/conf-I./src/include/log-I./src/include/network-I./src/include/upnp-I/home/leon/nvc/arm-hisiv100nptl-linux/includesrc/common/nv_conf.c-obuild/objs/hi3518/src/common/nv_conf.o/*省略中間部分*/arm-hisiv100nptl-linux-gcc-c-fPIC-Wall-g-ggdb-O0-DHI3518_CHIP-DLINUX-I./src/include-I./src/include/common-I./src/include/camera-I./src/include/conf-I./src/include/log-I./src/include/network-I./src/include/upnp-I/home/leon/nvc/arm-hisiv100nptl-linux/includesrc/network/misc/nv_net_udp.c-obuild/objs/hi3518/src/network/misc/nv_net_udp.o
src/network/misc/nv_net_udp.c:17:fatalerror:nv_net_tools.h:Nosuchfileordirectory
compilationterminated.make:***[build/objs/hi3518/src/network/misc/nv_net_udp.o]Error112345678
note: 在以上編譯過程中我們發現,編譯器提示說找不到nv_net_tools.h文件，而現實中我們也不需要這個文件的包含了，需要刪除包含nv_net_tools.h 文件中的該行代碼。
5.字元串提取 (命令行)
目標字元串
"from":"0802070975","to":"0802071013","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":012
需要提取 from , to, url , md5, level 等5個關鍵字後面的內容。
//提取 from 內容echo
"from":"0802070975","to":"0802071013","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0|sed"s/.*from:(.*)/1/"|cut-d','-f1
//提取 to 內容echo
"from":"0802070975","to":"0802071013","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0|sed"s/.*to:(.*)/1/"|cut-d','-f1
//提取 url 內容echo
"from":"0802070975","to":"0802071013","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0|sed"s/.*url:(.*)/1/"|cut-d','-f1
//提取 md5 內容echo
"from":"0802070975","to":"0802071013","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0|sed"s/.*md5:(.*)/1/"|cut-d','-f1
//提取 level 內容echo
"from":"0802070975","to":"0802071013","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0|sed"s/.*level:(.*)/1/"|cut-d','-f112345678910111213141516
6.字元串提取 (腳本文件)
ret_val=""from":"0804020982","to":"0804020998","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0"
echoret_valis:[$ret_val]from="$(echo$ret_val|sed's/.*from":(.*)/1/'|cut-d','-f1|sed's/"//g')"
echofrom:$from
to="$(echo$ret_val|sed's/.*to":(.*)/1/'|cut-d','-f1|sed's/"//g')"
echoto:$to
url="$(echo$ret_val|sed's/.*url":(.*)/1/'|cut-d','-f1|sed's/"//g')"
echourl:$url
md5="$(echo$ret_val|sed's/.*md5":(.*)/1/'|cut-d','-f1|sed's/"//g')"
echomd5:$md5
level="$(echo$ret_val|sed's/.*level":(.*)/1/'|cut-d','-f1|sed's/"//g')"
echolevel:$
執行結果：
ret_valis:["from":"0804020982","to":"0804020998","url":"http://cn.update.mynetvue.com:8060/firmware/.tar.gz","md5":"","level":0]
from:0804020982
to:0804020998
url:http://cn.update.mynetvue.com:8060/firmware/.tar.gzmd5:
level:0
I.總結
要注意命令行執行，與腳本文件執行之間的差異性。
2. linux 中如何截取2個字元串中間的字元
可以用awk、sed、tr、perl都能實現
set s = '"stratum":{"accepted_shares":1,"algorithm"'
set a = `echo $s | awk -F '["/:]' '{print $4}'`
