grep [options] [regex] [files]
/var/root # grep -n "o" *
hello.c:1:/* This C source can be compiled with:
hello.c:3: tcc -o hello hello.c
hello.c:5: or if you have more time:
hello.c:7: gcc -o hello hello.c
hello.c:10:#include <stdio.h>
hello.c:14: printf("Hello World\n");
txt:1:hello everyone.
cut [options] [files]
cut [-bn] [file] 或 cut [-c] [file] 或 cut [-df] [file]
/var/root # cut -b 3-5,8 txt llov is e b /var/root # cut -d "f" -f2 txt hello everyone. ile. bye bye ...
IFS 为linux默认分割符号
/var/root # echo "start${IFS}end"
start
end