Shell Programming and Scripting

abc.1
abc
abc_1
abc..1
abc*1
abc@1
abc def ghr
def......
ddef 5466 def ed 
def** 123445

abc
def

grep -wf file2 file1

abc.1
abc
abc..1
abc*1
abc@1
abc def ghr
def......
ddef 5466 def ed
def** 123445

abc
ddef 5466 def ed

awk '
NR==FNR {a[$1]=$1; next;}
{l=0; for (i=1; i<=NF; i++) if ($i in a) {print ; next;}}
' words_file infile

awk '
NR==FNR {a[$1]=$1; next;}
{l=0; for (i=1; i<=NF; i++) ($i in a) ? l++ : 0; if (l==1) print}
' words_file infile

egrep '(^|[[:blank:]]+)(abc|def)([[:blank:]]+|$)' infile

awk '
NR==FNR {a[$1]; next;}
{L=0; for (i=1; i<=NF; i++) if ($i in a) L++;} L==1
' words_file infile

\(\W\)abc\(\W\|$\)
\(\W\)def\(\W\|$\)

grep -f words_file infile