Sed: delete alphanumeric words from a file

Question

I have a file with a lot of text, what I want to do is delete all the alphanumeric words.

Example of words to be removed: gr8 2006 sdlfj435ljsa 232asa asld213 ladj2343asda asd!32 

How can I do this?

Answer 1

If you want to delete all words consisting of letters and numbers, leaving only words consisting of all numbers or all letters:

 sed 's/\([[:alpha:]]\+[[:digit:]]\+[[:alnum:]]*\|[[:digit:]]\+[[:alpha:]]\+[[:alnum:]]*\) \?//g' inputfile 

Example:

 $ echo 'abc def ghi 111 222 ab3 a34 43a a34a 4ab3' | sed 's/\<\([[:alpha:]]\+[[:digit:]]\+[[:alnum:]]*\|[[:digit:]]\+[[:alpha:]]\+[[:alnum:]]*\) \?//g' abc def ghi 111 222 

Answer 2

Assuming the only conclusion you wanted to get from your sample text is 2006 , and you have one word per line:

  sed '/[[:alpha:]]\+/{/[[:digit:]]\+/d}' /path/to/alnum/file 

Enter

 $ cat alnum gr8 2006 sdlFj435ljsa 232asa asld213 ladj2343asda asd!32 alpha 

Exit

 $ sed '/[[:alpha:]]\+/{/[[:digit:]]\+/d}' ./alnum 2006 alpha 

Answer 3

If the goal is to remove all alphanumeric words (strings consisting entirely of letters and numbers), then this sed command will work. It replaces all alphanumeric strings with nothing.

 sed 's/[[:alnum:]]*//g' < inputfile 

Note that character classes other than alnum (see man 7 regex ).

For the data in this example, this leaves only 6 blank lines and one ! (since this is the only non-alphanumeric character in the example data). Is this really what you are trying to do?

Answer 4

AWK solution:

 BEGIN { # Statement that will be executed once at the beginning. FS="[ \t]" # Set space and tab characters to be treated as word separator. } # Code below will execute for each line in file. { x=1 # Set initial word index to 1 (0 is the original string in array) fw=1 # Indicate that future matched word is a first word. This is needed to put newline and spaces correctly. while ( x<=NF ) { gsub(/[ \t]*/,"",$x) # Strip word. Remove any leading and trailing white-spaces. if (!match($x,"^[A-Za-z0-9]*$")) # Print word only if it does not match pure alphanumeric set of characters. { if (fw == 0) { printf (" %s", $x) # Print the word offsetting it with space in case if this is not a first match. } else { printf ("%s", $x) # Print word as is... fw=0 # ...and indicate that future matches are not first occurrences } } x++ # Increase word index number. } if (fw == 0) # Print newline only if we had matched some words and printed something. { printf ("\n") } } 

Assuming you have this script in script.awk' and data in data.txt , you have to invoke awk` as follows:

 awk -f ./test.awk ./data.txt 

For your file, it will produce:

 asd!32 

For more complex cases like this:

 gr8 2006 sdlfj435ljsa 232asa he!he lol asld213 f ladj2343asda asd!32 ab acd!s 

... this will produce this:

 he!he asd!32 acd!s 

Hope this helps. Good luck