linu 把文件中的字母小写转换为大写,大写转换为小写awk toupper tolower

cat aa.txt|tr "[a-z]" "A-Z"

[root@ob2 mytmp]# awk '{print toupper($0)}' aa2.txt
ETH0      LINK ENCAP:ETHERNET  HWADDR 00:0C:29:2B:B9:55 
          INET ADDR:192.168.79.130  BCAST:192.168.79.255  MASK:255.255.255.0
          INET6 ADDR: FE80::20C:29FF:FE2B:B955/64 SCOPE:LINK

tolower(str)

[root@ob2 mytmp]# awk '{print tolower($0)}' aa2.txt
eth0      link encap:ethernet  hwaddr 00:0c:29:2b:b9:55 
          inet addr:192.168.79.130  bcast:192.168.79.255  mask:255.255.255.0