add function to get string value from cgroup file
add function to get string value from cgroup file

Signed-off-by: Qiang Huang <488e06933c295c76472a67dbc6657ac40a756953@huawei.com>

HuKeping/runc,estesp/libcontainer,keloyang/runc,clnperez/runc,ChengTiesheng/runc,estesp/runc,balajibr/runc,dqminh/runc,marcosnils/runc,HardikDR/runc,rajasec/runc,vbatts/runc,markllama/runc,LK4D4/runc,InformatiQ/runc,jhjeong-kr/runc,docker/libcontainer,han-wang/runc,chenchun/runc,InformatiQ/runc,dqminh/runc,xiaochenshen/runc,ekuric/runc,navidshaikh/runc,jhjeong-kr/runc,cxxly/runc,ycaihua/runc,wangkirin/runc,navidshaikh/runc,estesp/runc,nkwilson/runc,hqhq/libcontainer,mrunalp/runc,lizf-os/runc,boucher/libcontainer,keloyang/libcontainer,Mashimiao/libcontainer,mheon/runc,shenxiaochen/libcontainer,rajasec/runc,willmtemple/runc,balajibr/runc,chenchun/runc,kimh/runc,hqhq/runc,dqminh/libcontainer,thaJeztah/libcontainer,mikebrow/runc,runcom/runc,maxamillion/runc,ddnbgroup/runc,mYmNeo/runc,albertoleal/runc,opencontainers/runc,HuKeping/runc,tangkun75/libcontainer,axsh/runc,intfrr/runc,subuser-security/runc,BrickXu/libcontainer,avagin/runc,wking/runc,cyphar/runc,markllama/runc,balajibr/runc,dieface/runc,inatatsu/runc,mikebrow/runc,rajasec/runc,talwai/runc,albertoleal/runc,docker/runc,stefanberger/runc,haijunTan/runc,adrianreber/runc,YujiOshima/runc,rhatdan/libcontainer,nkwilson/runc,rootfs/runc,carlye566/runc,xiaochenshen/runc,YujiOshima/runc,vbatts/runc,sunyuan3/runc,fabiokung/runc,rootfs/runc,maxamillion/runc,rhatdan/runc,ZJU-SEL/libcontainer,dieface/runc,ZJU-SEL/runc,cloudfoundry-incubator/runc,runcom/runc,hqhq/libcontainer,haijunTan/runc,haijunTan/runc,zenlinTechnofreak/runc,shishir-a412ed/runc,ekuric/runc,abduld/runc,boucher/runc,HuKeping/runc,clnperez/runc,dqminh/runc,cyphar/runc,kolyshkin/runc,runcom/runc,jwuwork/runc,keloyang/runc,crosbymichael/libcontainer,calavera/runc,willmtemple/runc,marcosnils/runc,WeiZhang555/runc,keloyang/runc,estesp/libcontainer,rhatdan/runc,cloudfoundry-incubator/runc,mheon/libcontainer,chenchun/runc,thaJeztah/libcontainer,zhangyancoder/libcontainer,jwuwork/runc,HardikDR/runc,rsampaio/runc,liuwharton/runc,mheon/runc,ycaihua/runc,ycaihua/libcontainer,wcwxyz/runc,mheon/libcontainer,dieface/runc,vbatts/runc,kimh/runc,mikebrow/runc,navidshaikh/runc,cloudfoundry-incubator/runc,dqminh/libcontainer,jhowardmsft/runc,talwai/runc,LTD-Beget/libcontainer,ycaihua/libcontainer,mheon/runc,keloyang/libcontainer,jhowardmsft/runc,talwai/runc,sallyom/runc,stefanberger/runc,wcwxyz/runc,docker/runc,subuser-security/runc,whosthatknocking/runc,YujiOshima/runc,booyaa/runc,cxxly/runc,shishir-a412ed/runc,adrianreber/runc,Microsoft/libcontainer,aidanhs/runc,keloyang/libcontainer,justincormack/runc,jhjeong-kr/runc,coolljt0725/runc,crosbymichael/libcontainer,BrickXu/libcontainer,LTD-Beget/libcontainer,boucher/libcontainer,LK4D4/runc,rsampaio/runc,opencontainers/runc,Microsoft/libcontainer,marcosnils/runc,kimh/runc,opencontainers/runc,lizf-os/runc,ZJU-SEL/runc,carlye566/runc,rsampaio/runc,gitido/runc,docker/runc,opencontainers/runc,coolljt0725/runc,InformatiQ/runc,meihuabo/runc,avagin/runc,boucher/runc,thaJeztah/libcontainer,ycaihua/libcontainer,sunyuan3/runc,meihuabo/runc,dqminh/runc,docker/libcontainer,liuwharton/runc,gitido/runc,justincormack/runc,rhatdan/libcontainer,ekuric/runc,xiaochenshen/runc,cxxly/runc,sallyom/runc,wangkirin/runc,shenxiaochen/libcontainer,docker/libcontainer,ycaihua/runc,laijs/runc,fabiokung/runc,clnperez/runc,w4ngyi/libcontainer,runcom/libcontainer,abduld/runc,runcom/libcontainer,sallyom/runc,aidanhs/runc,fabiokung/runc,kolyshkin/runc,crosbymichael/libcontainer,justincormack/runc,gwoo/runc,whuwxl/libcontainer,cyphar/runc,calavera/runc,LK4D4/runc,intfrr/runc,inatatsu/runc,zenlinTechnofreak/runc,wking/runc,ZJU-SEL/libcontainer,albertoleal/runc,BrickXu/libcontainer,avagin/runc,ddnbgroup/runc,estesp/libcontainer,whosthatknocking/runc,liuwharton/runc,mYmNeo/runc,LTD-Beget/libcontainer,axsh/runc,lizf-os/runc,rhatdan/libcontainer,gitido/runc,HardikDR/runc,coolljt0725/runc,Mashimiao/libcontainer,mapk0y/runc,wangkirin/runc,ddnbgroup/runc,mYmNeo/runc,whuwxl/libcontainer,jwuwork/runc,intfrr/runc,zhangyancoder/libcontainer,runcom/libcontainer,estesp/runc,dqminh/libcontainer,hxfeng/runc,mapk0y/runc,tangkun75/libcontainer,han-wang/runc,hxfeng/runc,shishir-a412ed/runc,w4ngyi/libcontainer,ChengTiesheng/runc,kolyshkin/runc,ZJU-SEL/runc,mheon/libcontainer,kolyshkin/runc,hqhq/libcontainer,hxfeng/runc,willmtemple/runc,mrunalp/runc,w4ngyi/libcontainer,laijs/runc,keloyang/libcontainer,nkwilson/runc,hqhq/runc,jhowardmsft/runc,ZJU-SEL/libcontainer,rootfs/runc,mapk0y/runc,ChengTiesheng/runc,booyaa/runc,whosthatknocking/runc,tangkun75/libcontainer,hqhq/runc,abduld/runc,boucher/runc,calavera/runc,crosbymichael/runc,mrunalp/runc,markllama/runc,stefanberger/runc,laijs/runc,axsh/runc,WeiZhang555/runc,maxamillion/runc,carlye566/runc,WeiZhang555/runc,inatatsu/runc,Microsoft/libcontainer,aidanhs/runc,sunyuan3/runc,boucher/libcontainer,wcwxyz/runc,shenxiaochen/libcontainer,adrianreber/runc,subuser-security/runc,han-wang/runc,zenlinTechnofreak/runc,rhatdan/runc,Mashimiao/libcontainer,crosbymichael/runc,booyaa/runc,crosbymichael/runc,wking/runc,meihuabo/runc,whuwxl/libcontainer,rhatdan/runc,zhangyancoder/libcontainer