仅在文件开头没有找到+ sed追加行

Question

I am writing a script that appends a line to the beginning of files in a directory. The following code below does that.

 find . -type d \(  -name ThirdParty  -o  -name 3rdParty -o \
                    -name 3rd_party \) \
        -prune -o -type f \( -name "*.java"  -o -name "*.cs"    -o \
                             -name "*.cpp"   -o -name "*.cxx"   -o \
                             -name "*.cc"    -o -name "*.c"     -o \
                             -name "*.h"     -o -name "*.scala" -o \
                             -name "*.css"   -o -name "*.js" \) \
      -print0 | 
xargs -0 sed -i  '1s/^/\/*RIGHTS AND ETC ETC ETC/*'

However, I want to add this line ONLY if it is not already in the file. I have tried using grep and piping prior to using sed as such:

grep -q "/*RIGHTS AND ETC ETC ETC/*" | sed -i....

but, when I run the script I get sed: no input files . I am simply running this script in a directory so there are no input files. Thank you.

Answer 1

Your grep command doesn't print anything, because you used the -q option; it just sets the exit status based on whether the file matched.

You want to print all the filenames that don't match, so you can pass those filenames to sed . You can do that with the -L option, along with -z to use a null terminator rather than newline (like the -print0 option in find ).

You should also use -F to treat the string as a fixed string, rather than a regular expression pattern.

find . -type d \( -name ThirdParty -o -name 3rdParty -o -name 3rd_party \) -prune \
    -o -type f \( -name "*.java" -o -name "*.cs" -o -name "*.cpp" -o -name "*.cxx" -o -name "*.cc" -o -name "*.c" -o -name "*.h" -o -name "*.scala" -o -name "*.css" -o -name "*.js" \) -print0 |
xargs -0 grep -Lz -F "/*RIGHTS AND ETC ETC ETC/*" |
xargs -0 sed -i ...

Answer 2

grep isn't needed. sed can do a negative search, and make the i nsert conditional:

... -print0 | xargs -0 sed -i '1{/^\/\*RIGHTS AND ETC ETC ETC\*\/$/!i\
/\*RIGHTS AND ETC ETC ETC\*/
}'

---

Notes:

• the linefeeds in the three lines of code are necessary for i to work correctly.

• it's unclear whether the * s are literal or not, so they've been quoted like so \\* .

Answer 3

This might work for you (GNU sed and find):

(var="/*RIGHTS AND ETC ETC ETC/*" ;
find whatever  \! -exec grep -qF "$var" {} \; -exec sed -i '1i\'"$var" {} \;)

Where whatever are the initial find commands.

This will only insert the variable var if the grep did not find var anywhere in each entire file.