Find and append to files in Unix - shell

I am trying to find files by filename and write to them.
find ./ -name "filename" -type f -exec echo "some string" >> {} \;
This creates a file named {} and writes the string to it for every match instead of writing to the files found.

Try:
... -exec sed '$asome string' -i {} \;

You can spawn a subshell as part of the -exec and then use redirection as usual:
find . -name "filename" -type f -exec bash -c 'echo "some string" >> "$1"' _ {} \;
_ is a dummy handle for $0 within bash -c.

Related

From Bash I would like to use find to execute 2 commands on the same file, so I can output the file name and metadata about the file

From bash I need to execute 2 commands on specific files recursively. I am trying to print the filename and meta information at the same time. I need to combine the following 2 commands so first a filename is printed, then the metadata for that file is printed, and then repeat for the next file.
I print the file name with:
find . -wholename '*word/test.wsp -exec echo {} \;
And I print the meta-data with:
find . -wholename ‘*word/test\.wsp’ -exec whisper-info {} \;
However, the second command does not print the filename, so I am unsure which files the meta-data belongs to.
How can I execute the 2 commands simutaneously?
I've tried:
find . -wholename '*word/test.wsp -exec echo {} && whisper-info {} \;
find . -wholename '*word/test.wsp -exec echo && whisper-info {} \;
find . -wholename '*word/test.wsp -exec echo {} && -exec whisper-info {} \;
find . -wholename '*word/test.wsp -exec echo {} \; && whisper-info {} \;
find . -wholename '*word/test.wsp -exec echo {} \; && -exec whisper-info {} \;
And a lot of other combinations.
Just put two -execs.
find . -wholename '*word/test.wsp' -exec echo {} \; -exec whisper-info {} \;
If you have GNU find, perhaps prefer its built-in printf rather than an external echo.
You also consistently seem to have misplaced the closing quote. The string with the wildcard needr to be quoted or escaped to prevent the shell from expanding the wildcard before find runs.
-exec require a single command, but that command can be a shell that executes an arbitrary script consisting of your two commands.
find . -wholename '*word/test.wsp' -exec sh -c 'echo "$1"; whisper-info "$1"' _ {} \;
A few notes:
{} is not embedded in the command. Let the command be a static script that accepts an argument, instead.
_ is a dummy value used to set $0 in the shell.
You can avoid spawning quite so many shells by including a loop in the shell to iterate over multiple arguments provided by find -exec ... +
find . -wholename '*word/test.wsp' -exec sh -c 'for f; do echo "$f"; whisper-info "$f"; done' _ {} +
for f; do ...; done is short for for f in "$#"; do ...; done.

find -exec basename {} vs find -exec echo $(basename {})

I'm sure I'm missing something but I can't figure it out. Given:
$ find -type f
./hello.txt
./wow.txt
./yay.txt
how come the next two commands render different results?
$ find -type f -exec basename {} \;
hello.txt
wow.txt
yay.txt
$ find -type f -exec echo $(basename {}) \;
./hello.txt
./wow.txt
./yay.txt
$(basename {}) is evaluated before the command runs. The result is {} so the command echo $(basename {}) becomes echo {} and basename is not run for each file.
A quick debug on that using the bash -x debugger demonstrated this,
[The example is my own, just for demonstration purposes]
bash -xc 'find -type f -name "*.sh" -exec echo $(basename {}) \;'
++ basename '{}'
+ find -type f -name '*.sh' -exec echo '{}' ';'
./1.sh
./abcd/another_file_1_not_ok.sh
./abcd/another_file_2_not_ok.sh
./abcd/another_file_3_not_ok.sh
And for just basename {}
bash -xc 'find -type f -name "*.sh" -exec basename {} \;'
+ find -type f -name '*.sh' -exec basename '{}' ';'
1.sh
another_file_1_not_ok.sh
another_file_2_not_ok.sh
another_file_3_not_ok.sh
As you can see in the first example, echo $(basename {}) gets resolved in two steps, basename {} is nothing but the basename on the actual file (which outputs the plain file name) which is then interpreted as echo {}. So it is nothing but mimic-ing the exact behaviour when you use find with exec and echo the files as
bash -xc 'find -type f -name "*.sh" -exec echo {} \;'
+ find -type f -name '*.sh' -exec echo '{}' ';'
./1.sh
./abcd/another_file_1_not_ok.sh
./abcd/another_file_2_not_ok.sh
./abcd/another_file_3_not_ok.sh

Bash: execute a command on all files with extension recursively

I'm trying to use the following command:
herbalizer file_name.haml > file_name.erb
Here the file_name.haml is the file name, obviously.
How can I apply this command to all haml files in current directory recursively to all sub-directories? Filename should stay the same as mentioned above, so applying on abc.haml would be herbalizer abc.haml > abc.erb
So far: find . -type f -exec herbalizer {} \;
You're pretty close. You can use basename to strip the extension of the name of each file you find:
find . -type f -name \*.haml -exec sh -c 'herbalizer "{}" > "$(dirname {})/$(basename {} .haml).erb"' \;
I wrapped the i/o redirection in a shell command line. Filenames are enclosed in quotes in case a filename or path component contains spaces.
PS. That got you the job done, but it wasn't very elegant; so here's an alternative that uses bash's built-in substitution:
find . -type f -name \*.haml -exec bash -c 'FN="{}"; herbalizer "{}" > "${FN%.haml}.erb"' \;
You can use basename, dirname and find to get your desired results:
find . -type f -name "*.haml" | while read fname
> do
> herbalizer ${fname} > $(dirname $fname)/$(basename $fname .haml).erb
> done
Another simple method as suggested in the comments sections by #Dummy00001 is:
find . -type f -name "*.haml" | while read fname
> do
> herbalizer ${fname} > ${fname%.haml}.erb
> done
Further reference: Parameter substitution

"find -exec print" does not work

> find . -type f -exec print {} \;
find: cannot execute print:: No such file or directory
> find . -type f -exec echo {} \;
f1.txt
f2.txt
...
Why "find -exec print" does not work?
Shell - ksh.
I think print is a shell builtin, not an executable.

find -exec with multiple commands

I am trying to use find -exec with multiple commands without any success. Does anybody know if commands such as the following are possible?
find *.txt -exec echo "$(tail -1 '{}'),$(ls '{}')" \;
Basically, I am trying to print the last line of each txt file in the current directory and print at the end of the line, a comma followed by the filename.
find accepts multiple -exec portions to the command. For example:
find . -name "*.txt" -exec echo {} \; -exec grep banana {} \;
Note that in this case the second command will only run if the first one returns successfully, as mentioned by #Caleb. If you want both commands to run regardless of their success or failure, you could use this construct:
find . -name "*.txt" \( -exec echo {} \; -o -exec true \; \) -exec grep banana {} \;
find . -type d -exec sh -c "echo -n {}; echo -n ' x '; echo {}" \;
One of the following:
find *.txt -exec awk 'END {print $0 "," FILENAME}' {} \;
find *.txt -exec sh -c 'echo "$(tail -n 1 "$1"),$1"' _ {} \;
find *.txt -exec sh -c 'echo "$(sed -n "\$p" "$1"),$1"' _ {} \;
Another way is like this:
multiple_cmd() {
tail -n1 $1;
ls $1
};
export -f multiple_cmd;
find *.txt -exec bash -c 'multiple_cmd "$0"' {} \;
in one line
multiple_cmd() { tail -1 $1; ls $1 }; export -f multiple_cmd; find *.txt -exec bash -c 'multiple_cmd "$0"' {} \;
"multiple_cmd()" - is a function
"export -f multiple_cmd" - will export it so any other subshell can see it
"find *.txt -exec bash -c 'multiple_cmd "$0"' {} \;" - find that will execute the function on your example
In this way multiple_cmd can be as long and as complex, as you need.
Hope this helps.
There's an easier way:
find ... | while read -r file; do
echo "look at my $file, my $file is amazing";
done
Alternatively:
while read -r file; do
echo "look at my $file, my $file is amazing";
done <<< "$(find ...)"
Extending #Tinker's answer,
In my case, I needed to make a command | command | command inside the -exec to print both the filename and the found text in files containing a certain text.
I was able to do it with:
find . -name config -type f \( -exec grep "bitbucket" {} \; -a -exec echo {} \; \)
the result is:
url = git#bitbucket.org:a/a.git
./a/.git/config
url = git#bitbucket.org:b/b.git
./b/.git/config
url = git#bitbucket.org:c/c.git
./c/.git/config
I don't know if you can do this with find, but an alternate solution would be to create a shell script and to run this with find.
lastline.sh:
echo $(tail -1 $1),$1
Make the script executable
chmod +x lastline.sh
Use find:
find . -name "*.txt" -exec ./lastline.sh {} \;
Thanks to Camilo Martin, I was able to answer a related question:
What I wanted to do was
find ... -exec zcat {} | wc -l \;
which didn't work. However,
find ... | while read -r file; do echo "$file: `zcat $file | wc -l`"; done
does work, so thank you!
1st answer of Denis is the answer to resolve the trouble. But in fact it is no more a find with several commands in only one exec like the title suggest. To answer the one exec with several commands thing we will have to look for something else to resolv. Here is a example:
Keep last 10000 lines of .log files which has been modified in the last 7 days using 1 exec command using severals {} references
1) see what the command will do on which files:
find / -name "*.log" -a -type f -a -mtime -7 -exec sh -c "echo tail -10000 {} \> fictmp; echo cat fictmp \> {} " \;
2) Do it: (note no more "\>" but only ">" this is wanted)
find / -name "*.log" -a -type f -a -mtime -7 -exec sh -c "tail -10000 {} > fictmp; cat fictmp > {} ; rm fictmp" \;
I usually embed the find in a small for loop one liner, where the find is executed in a subcommand with $().
Your command would look like this then:
for f in $(find *.txt); do echo "$(tail -1 $f), $(ls $f)"; done
The good thing is that instead of {} you just use $f and instead of the -exec … you write all your commands between do and ; done.
Not sure what you actually want to do, but maybe something like this?
for f in $(find *.txt); do echo $f; tail -1 $f; ls -l $f; echo; done
should use xargs :)
find *.txt -type f -exec tail -1 {} \; | xargs -ICONSTANT echo $(pwd),CONSTANT
another one (working on osx)
find *.txt -type f -exec echo ,$(PWD) {} + -exec tail -1 {} + | tr ' ' '/'
A find+xargs answer.
The example below finds all .html files and creates a copy with the .BAK extension appended (e.g. 1.html > 1.html.BAK).
Single command with multiple placeholders
find . -iname "*.html" -print0 | xargs -0 -I {} cp -- "{}" "{}.BAK"
Multiple commands with multiple placeholders
find . -iname "*.html" -print0 | xargs -0 -I {} echo "cp -- {} {}.BAK ; echo {} >> /tmp/log.txt" | sh
# if you need to do anything bash-specific then pipe to bash instead of sh
This command will also work with files that start with a hyphen or contain spaces such as -my file.html thanks to parameter quoting and the -- after cp which signals to cp the end of parameters and the beginning of the actual file names.
-print0 pipes the results with null-byte terminators.
for xargs the -I {} parameter defines {} as the placeholder; you can use whichever placeholder you like; -0 indicates that input items are null-separated.
I found this solution (maybe it is already said in a comment, but I could not find any answer with this)
you can execute MULTIPLE COMMANDS in a row using "bash -c"
find . <SOMETHING> -exec bash -c "EXECUTE 1 && EXECUTE 2 ; EXECUTE 3" \;
in your case
find . -name "*.txt" -exec bash -c "tail -1 '{}' && ls '{}'" \;
i tested it with a test file:
[gek#tuffoserver tmp]$ ls *.txt
casualfile.txt
[gek#tuffoserver tmp]$ find . -name "*.txt" -exec bash -c "tail -1 '{}' && ls '{}'" \;
testonline1=some TEXT
./casualfile.txt
Here is my bash script that you can use to find multiple files and then process them all using a command.
Example of usage. This command applies a file linux command to each found file:
./finder.sh file fb2 txt
Finder script:
# Find files and process them using an external command.
# Usage:
# ./finder.sh ./processing_script.sh txt fb2 fb2.zip doc docx
counter=0
find_results=()
for ext in "${#:2}"
do
# #see https://stackoverflow.com/a/54561526/10452175
readarray -d '' ext_results < <(find . -type f -name "*.${ext}" -print0)
for file in "${ext_results[#]}"
do
counter=$((counter+1))
find_results+=("${file}")
echo ${counter}") ${file}"
done
done
countOfResults=$((counter))
echo -e "Found ${countOfResults} files.\n"
echo "Processing..."
counter=0
for file in "${find_results[#]}"
do
counter=$((counter+1))
echo -n ${counter}"/${countOfResults}) "
eval "$1 '${file}'"
done
echo "All files have been processed."

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