Bash: tell if a file is included in another

Question

I'm trying to compare the content of two files and tell if the content of one is totally included in another (meaning if one file has three lines, A, B and C, can I find those three lines, in that order, in the second file). I've looked at diff and grep but wasn't able to find the relevant option (if any).

Examples:

file1.txt   file2.txt  <= should return true (file2 is included in file1)
---------   ---------
abc         def
def         ghi
ghi
jkl    

file1.txt   file2.txt  <= should return false (file2 is not included in file1)
---------   ---------
abc         abc
def         ghi
ghi
jkl    

Any idea?

Answer 1

Using the answer from here

Use the following python function:

def sublistExists(list1, list2):
    return ''.join(map(str, list2)) in ''.join(map(str, list1))

In action:

In [35]: a=[i.strip() for i in open("f1")]
In [36]: b=[i.strip() for i in open("f2")]
In [37]: c=[i.strip() for i in open("f3")]

In [38]: a
Out[38]: ['abc', 'def', 'ghi', 'jkl']

In [39]: b
Out[39]: ['def', 'ghi']

In [40]: c
Out[40]: ['abc', 'ghi']

In [41]: sublistExists(a, b)
Out[41]: True

In [42]: sublistExists(a, c)
Out[42]: False

Answer 2

Assuming your file2.txt does not contain characters with special meaning for regular expressions, you can use:

grep "$(<file2.txt)" file1.txt

Answer 3

This should work even if your file2.txt contains special characters:

cp file1.txt file_read.txt

while read -r a_line ; do
   first_line_found=$( fgrep -nx "${a_line}" file_read.txt 2>/dev/null | head -1 )
   if [ -z "$first_line_found" ]; 
   then 
        exit 1 # we couldn't find a_line in the file_read.txt
   else
        { echo "1,${first_line_found}d" ; echo "w" ; } | ed file_read.txt  #we delete up to line_found
   fi   
done < file2.txt
exit 0

(the "exit 0" is there for "readability" so one can see easily that it exits with 1 only if fgrep can't find a line in file1.txt. It's not needed)

(fgrep is a literral grep, searching for a string (not a regexp))

(I haven't tested the above, it's a general idea. I hope it does work though ^^)

the "-x" force it to match lines exactly, ie, no additionnal characters (ie : "to" can no longer match "toto". Only "toto" will match "toto" when adding -x)

Answer 4

please try if this awk "one-liner" ^_^ works for your real file. for the example files in your question, it worked:

awk 'FNR==NR{a=a $0;next}{b=b $0}
END{while(match(b,a,m)){
    if(m[0]==a) {print "included";exit}
    b=substr(b,RSTART+RLENGTH)
   }
    print "not included"
}' file2 file1