CODEWITHSUNDEEP
bashfindexpansion
John Halbert
John Halbert

Reputation: 23

How to surround find's -name parameter with wildcards before and after a variable?

I have a list of newline-separated strings. I need to iterate through each line, and use the argument surrounded with wildcards. The end result will append the found files to another text file. Here's some of what I've tried so far:

cat < ${INPUT} | while read -r line; do find ${SEARCH_DIR} -name $(eval *"$line"*); done >> ${OUTPUT}

I've tried many variations of eval/$() etc, but I haven't found a way to get both of the asterisks to remain. Mostly, I get things that resemble *$itemFromList, but it's missing the second asterisk, resulting in the file not being found. I think this may have something to do with bash expansion, but I haven't had any luck with the resources I've found so far.

Basically, need to supply the -name parameter with something that looks like *$itemFromList*, because the file has words both before and after the value I'm searching for.

Any ideas?

Upvotes: 2

Views: 727

Answers (1)

Charles Duffy
Charles Duffy

Reputation: 295278

Use double quotes to prevent the asterisk from being interpreted as an instruction to the shell rather than find.

-name "*$line*"

Thus:

while read -r line; do
  line=${line%$'\r'}  # strip trailing CRs if input file is in DOS format
  find "$SEARCH_DIR" -name "*$line*"
done <"$INPUT" >>"$OUTPUT"

...or, better:

#!/usr/bin/env bash

## use lower-case variable names
input=$1
output=$2

args=( -false )                 # for our future find command line, start with -false
while read -r line; do
  line=${line%$'\r'}            # strip trailing CR if present
  [[ $line ]] || continue       # skip empty lines
  args+=( -o -name "*$line*" )  # add an OR clause matching if this line's substring exists
done <"$input"

# since our last command is find, use "exec" to let it replace the shell in memory
exec find "$SEARCH_DIR" '(' "${args[@]}" ')' -print >"$output"

Note:

  • The shebang specifying bash ensures that extended syntax, such as arrays, are available.
  • See BashFAQ #50 for a discussion of why an array is the correct structure to use to collect a list of command-line arguments.
  • See the fourth paragraph of http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html for the relevant POSIX specification on environment and shell variable naming conventions: All-caps names are used for variables with meaning to the shell itself, or to POSIX-specified tools; lowercase names are reserved for application use. That script you're writing? For purposes of the spec, it's an application.

Upvotes: 3

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