find if filename contains a certain string in bash script

Question

I have a bunch of output files in a directory, such as: a.out, b.out c.out, etc.

I want to search through the output files and if the output file name contains a certain string (such as "a"), then it will print the corresponding output file "a.out" to screen.

After I cd-ed into the output files directory, here's my code:

OUT_FILE="*.out"
OT=$OUT_FILE
STRING="a"

for file in "$OT";do
  if [[$file == *"$STRING"*]];then
    echo $file
  fi
done

The error I received is [[*.out: command not found. It looks like $file is interpreted as $OT, not as individual files that matches $OT.

But when I removed the if statement and just did a for-loop to echo each $file, the output gave me all the files that ended with .out.

Would love some help to understand what I did wrong. Thanks in advance.

Wildcards (like *.out) aren't expanded inside double-quotes or on the right side of an assignment, so yours never gets converted to a list of files (until you echo it without double-quotes). Also, you need spaces between [[, the elements of the comparison, and ]]. Spaces are critical delimiters in the shell; do not leave them out. — Gordon Davisson
– Gordon Davisson, Commented May 13, 2018 at 23:14

Kusalananda · Accepted Answer · 2018-05-14 08:46:47Z

25

You need space after [[ and before ]]:

for file in *.out;do
  if [[ "$file" == *"$STRING"* ]];then
    printf '%s\n' "$file"
  fi
done

or just

for file in *"$STRING"*.out; do
    printf '%s\n' "$file"
done

or

printf '%s\n' *"$STRING"*.out

answered May 14, 2018 at 8:46

Kusalananda

15.8k3 gold badges47 silver badges54 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

katiayx Over a year ago

Could you explain what is '%s\n? Thanks!

Kusalananda Over a year ago

@katiayx %s is the printf format specifier for "a string". The %s acts like a placeholder for the next argument on the command line. The value of the next argument will replace %s in the output. The \n will be replaced by a newline. If printf is given more argument than placeholders in the format string, the format string will be reused.

Bhagesh Arora Over a year ago

@Kusalananda We need to check for particular directory also, Where we can mention directory path

Kusalananda Over a year ago

@BhageshArora If the directory path is in DIRPATH, then use for file in "$DIRPATH"/*"$STRING"*.out; do ...; done.

Bhagesh Arora Over a year ago

@Kusalananda Not working propery, cursor is going in both if and else condition. Inside the for loop.

|

Jens · Accepted Answer · 2018-05-15 11:39:54Z

7

Without bashisms like [[ (works in any Bourne-heritage shell) and blindingly fast since it does not fork any utility program:

for file in *.out; do
  case $file in
    (*a*) printf '%s\n' "$file";;
  esac
done

If you want you can replace (*a*) with (*$STRING*).

Alternative if you have a find that understands -maxdepth 1:

find . -maxdepth 1 -name \*"$STRING"\*.out

PS: Your question is a bit unclear. The code you posted tests for a in the file name (and so does my code). But your text suggests you want to search for a in the file contents. Which is it? Can you clarify?

edited May 15, 2018 at 11:39

answered May 14, 2018 at 8:55

Jens

73.3k16 gold badges134 silver badges186 bronze badges

2 Comments

katiayx Over a year ago

My goal is to search for a in the file name. Sorry for the confusion.

Jens Over a year ago

@katiayx Then the easiest is probably for i in *"$STRING"*.out; do echo "$i"; done, assuming there is at least one match.

Collectives™ on Stack Overflow

find if filename contains a certain string in bash script

2 Answers 2

7 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related