I'm looking for a simple bash script which, when given the name of a system header, will return its full path from which it would be read in a #include <header> statement. I already have an analogous thing for looking up the library archive used by linker.
ld -verbose -lz -L/some/other/dir | grep succeeded | sed -e 's/^\s*attempt to open //' -e 's/ succeeded\s*$//'
For example, this will return the path of libz archive (/lib/x86_64-linux-gnu/libz.so on my system).
For the requested script I know that I could take a list of include directories used by gcc and search them for the file myself, but I'm looking for a more accurate simulation of what's happening inside the preprocessor (unless it's that simple).
Pipe the input to preprocessor and then process the output. Gcc preprocessor output inserts # lines with information and flags that you can parse.
$ f=stdlib.h
$ echo "#include <$f>" | gcc -xc -E - | sed '\~# [0-9]* "\([^"]*/'"$f"'\)" 1 .*~!d; s//\1/'
/usr/include/stdlib.h
It can output multiple files, because gcc has #include_next and can improperly detect in some complicated cases where multiple filenames are included with the same name, like in f=limits.h. So you could also filter exactly second line, knowing that the first line is always going to be stdc-predef.h:
$ f=limits.h; echo "#include <$f>" | gcc -xc -E - | sed '/# [0-9]* "\([^"]*\)" 1 .*/!d;s//\1/' | sed '2!d'
/usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/include-fixed/limits.h
But really search the include paths yourself, it's not that hard:
$ f=limits.h; echo | gcc -E -Wp,-v - 2>&1 | sed '\~^ /~!d; s/ //' | while IFS= read -r path; do if [[ -e "$path/$f" ]]; then echo "$path/$f"; break; fi; done
/usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/include-fixed/limits.h
You can use the preprocessor to do the work:
user#host:~$ echo "#include <stdio.h>" > testx.c && gcc -M testx.c | grep 'stdio.h'
testx.o: testx.c /usr/include/stdc-predef.h /usr/include/stdio.h \
You can add a bit bash-fu to cut the part you are interested in
Is it possible to redirect output of a file to ls.
Example: file has a / in it and I want to direct that to ls to get the content of the / directory. When I try ls < file this does not work
You can use xargs or command substitution to achieve this.
Use xargs
The key is knowledge of the xargs command.
If you have a list of files in a file called files_to_change, you
can print them with the following one liner:
cat files_to_change | xargs ls
Use command substitution
An alternate method is to use command substitution. This works
the same as above.
Two different one-liners, using different syntax:
ls `cat files_to_change`
ls $(cat files_to_change)
It won't matter if they are files or directories, and you can run any command on them.
If the contents of file_to_change was:
/usr/bin/
/bin/
cat files_to_change | xargs ls and ls $(cat files_to_change) would be equivalent to running:
$ ls /usr/bin/
$ ls /bin/
The output on the console should be what you want.
You need to use xargs. This very useful utility runs a command with arguments which are passed in as input:
cat myfile | xargs ls
ls 'cat your_file'
beware, the ' is the altGr+7 char (but used for formatting here !)
Looking for solaris command for getting list of all files containing search pattern (recursively). I know how to do it for linux but same command is not working in solaris:
bash-3.2# uname -a
SunOS D1NCIC-CL01 5.10 Generic_148888-03 sun4u sparc SUNW,Sun-Fire-15000
bash-3.2# find . -type f -print0 | xargs -0 grep -l "contentInFile"
xargs: illegal option -- 0
xargs: Usage: xargs: [-t] [-p] [-e[eofstr]] [-E eofstr] [-I replstr] [-i[replstr]] [-L #] [-l[#]] [-n # [-x]] [-s size] [cmd [args ...]]
find: bad option -print0
find: [-H | -L] path-list predicate-list
As is so often the case when combined with find, xargs is useless here. You can run this portable command on both Solaris and Linux to get what you want:
find . -type f -exec grep -l "contentInFile" {} +
If your filenames don't contain any whitespace, simply use -print and omit the -0 from xargs.
If they do, upgrade to Solaris 11, and use /usr/gnu/bin/find and /usr/gnu/bin/xargs (GNU Tools out of the box in Solaris 11).
Alternatively, if you're stuck on Solaris 10, install the GNU Find Utilities (How do I grep recursively?), or one of the alternative search tools suggested in How do I grep recursively? (Ag, ack).
I have multiple(more than 100) .c files and I want to change a particular text from all the file in which that text exists. I am using ubuntu!
How can I do it?(I will prefer command line rather than installing any application)
Thanks a lot!
OLD=searchtext
NEW=replacedtext
YOURFILE=/path/to/your/file
TMPFILE=`mktemp`
sed "s/$OLD/$NEW/g" $YOURFILE > $TMPFILE && mv $TMPFILE $YOURFILE
rm -rf $TMPFILE
you can also use find to find your files:
find /path/to/parent/dir -name "*.c" -exec sed 's/$OLD/$NEW/g' {} > $TMPFILE && mv $TMPFILE {} \;
find /path/to/parent/dir -name "*.c" finds all files with name *.c under /path/to/parent/dir. -exec command {} \; executes the command in the found file. {} stands for the found file.
You should check out sed, which lets your replace some text with other text (among other things)
example
sed s/day/night/ oldfile newfile
will change all occurences of "day" with "night" in the oldfile, and store the new, changed version in the newfile
to run on many files, there are a few things you could do:
use foreach in your favorite shell
use find like this
find . -name "namepattern" -exec sed -i "sed-expr" "{}" \;
use file patterns like this: sed -i "sed-expr" *pattern?.cpp
where *pattern?.cpp is just a name pattern for all files that starts with some string, then has "pattern" in them, and has any letter and a ".cpp" suffix
How do I find out the files in the current directory which do not contain the word foo (using grep)?
If your grep has the -L (or --files-without-match) option:
$ grep -L "foo" *
You can do it with grep alone (without find).
grep -riL "foo" .
This is the explanation of the parameters used on grep
-L, --files-without-match
each file processed.
-R, -r, --recursive
Recursively search subdirectories listed.
-i, --ignore-case
Perform case insensitive matching.
If you use l (lowercased) you will get the opposite (files with matches)
-l, --files-with-matches
Only the names of files containing selected lines are written
Take a look at ack. It does the .svn exclusion for you automatically, gives you Perl regular expressions, and is a simple download of a single Perl program.
The equivalent of what you're looking for should be, in ack:
ack -L foo
The following command gives me all the files that do not contain the pattern foo:
find . -not -ipath '.*svn*' -exec grep -H -E -o -c "foo" {} \; | grep 0
The following command excludes the need for the find to filter out the svn folders by using a second grep.
grep -rL "foo" ./* | grep -v "\.svn"
If you are using git, this searches all of the tracked files:
git grep -L "foo"
and you can search in a subset of tracked files if you have ** subdirectory globbing turned on (shopt -s globstar in .bashrc, see this):
git grep -L "foo" -- **/*.cpp
You will actually need:
find . -not -ipath '.*svn*' -exec grep -H -E -o -c "foo" {} \; | grep :0\$
I had good luck with
grep -H -E -o -c "foo" */*/*.ext | grep ext:0
My attempts with grep -v just gave me all the lines without "foo".
Problem
I need to refactor a large project which uses .phtml files to write out HTML using inline PHP code. I want to use Mustache templates instead. I want to find any .phtml giles which do not contain the string new Mustache as these still need to be rewritten.
Solution
find . -iname '*.phtml' -exec grep -H -E -o -c 'new Mustache' {} \; | grep :0$ | sed 's/..$//'
Explanation
Before the pipes:
Find
find . Find files recursively, starting in this directory
-iname '*.phtml' Filename must contain .phtml (the i makes it case-insensitive)
-exec 'grep -H -E -o -c 'new Mustache' {}' Run the grep command on each of the matched paths
Grep
-H Always print filename headers with output lines.
-E Interpret pattern as an extended regular expression (i.e. force grep
to behave as egrep).
-o Prints only the matching part of the lines.
-c Only a count of selected lines is written to standard output.
This will give me a list of all file paths ending in .phtml, with a count of the number of times the string new Mustache occurs in each of them.
$> find . -iname '*.phtml$' -exec 'grep -H -E -o -c 'new Mustache' {}'\;
./app/MyApp/Customer/View/Account/quickcodemanagestore.phtml:0
./app/MyApp/Customer/View/Account/studio.phtml:0
./app/MyApp/Customer/View/Account/orders.phtml:1
./app/MyApp/Customer/View/Account/banking.phtml:1
./app/MyApp/Customer/View/Account/applycomplete.phtml:1
./app/MyApp/Customer/View/Account/catalogue.phtml:1
./app/MyApp/Customer/View/Account/classadd.phtml:0
./app/MyApp/Customer/View/Account/orders-trade.phtml:0
The first pipe grep :0$ filters this list to only include lines ending in :0:
$> find . -iname '*.phtml' -exec grep -H -E -o -c 'new Mustache' {} \; | grep :0$
./app/MyApp/Customer/View/Account/quickcodemanagestore.phtml:0
./app/MyApp/Customer/View/Account/studio.phtml:0
./app/MyApp/Customer/View/Account/classadd.phtml:0
./app/MyApp/Customer/View/Account/orders-trade.phtml:0
The second pipe sed 's/..$//' strips off the final two characters of each line, leaving just the file paths.
$> find . -iname '*.phtml' -exec grep -H -E -o -c 'new Mustache' {} \; | grep :0$ | sed 's/..$//'
./app/MyApp/Customer/View/Account/quickcodemanagestore.phtml
./app/MyApp/Customer/View/Account/studio.phtml
./app/MyApp/Customer/View/Account/classadd.phtml
./app/MyApp/Customer/View/Account/orders-trade.phtml
When you use find, you have two basic options: filter results out after find has completed searching or use some built in option that will prevent find from considering those files and dirs matching some given pattern.
If you use the former approach on a high number of files and dirs. You will be using a lot of CPU and RAM just to pass the result on to a second process which will in turn filter out results by using a lot of resources as well.
If you use the -not keyword which is a find argument, you will be preventing any path matching the string on the -name or -regex argument behind from being considered, which will be much more efficient.
find . -not -regex ".*/foo/.*" -regex ".*"
Then, any path that is not filtered out by -not will be captured by the subsequent -regex arguments.
For completeness the ripgrep version:
rg --files-without-match "pattern"
You can combine with file type and search path, e.g.
rg --files-without-match -t ruby "frozen_string_literal: true" app/
another alternative when grep doesn't have the -L option (IBM AIX for example), with nothing but grep and the shell :
for file in * ; do grep -q 'my_pattern' $file || echo $file ; done
My grep does not have any -L option. I do find workaround to achieve this.
The ideas are :
to dump all the file name containing the deserved string to a txt1.txt.
dump all the file name in the directory to a txt2.txt.
make the difference between the 2 dump file with diff command.
grep 'foo' *.log | cut -c1-14 | uniq > txt1.txt
grep * *.log | cut -c1-14 | uniq > txt2.txt
diff txt1.txt txt2.txt | grep ">"
find *20161109* -mtime -2|grep -vwE "(TRIGGER)"
You can specify the filter under "find" and the exclusion string under "grep -vwE". Use mtime under find if you need to filter on modified time too.
Open bug report
As commented by #tukan, there is an open bug report for Ag regarding the -L/--files-without-matches flag:
ggreer/the_silver_searcher: #238 - --files-without-matches does not work properly
As there is little progress to the bug report, the -L option mentioned below should not be relied on, not as long as the bug has not been resolved. Use different approaches presented in this thread instead. Citing a comment for the bug report [emphasis mine]:
Any updates on this? -L completely ignores matches on the first line of the file. Seems like if this isn't going to be fixed soon, the flag should be removed entirely, as it effectively does not work as advertised at all.
The Silver Searcher - Ag (intended function - see bug report)
As a powerful alternative to grep, you could use the The Silver Searcher - Ag:
A code searching tool similar to ack, with a focus on speed.
Looking at man ag, we find the -L or --files-without-matches option:
...
OPTIONS
...
-L --files-without-matches
Only print the names of files that don´t contain matches.
I.e., to recursively search for files that do not match foo, from current directory:
ag -L foo
To only search current directory for files that do not match foo, simply specify --depth=0 for the recursion:
ag -L foo --depth 0
This may help others. I have mix of files Go and with test files. But I only need .go files. So I used
ls *.go | grep -v "_test.go"
-v, --invert-match select non-matching lines see https://stackoverflow.com/a/3548465
Also one can use this with vscode to open all the files from terminal
code $(ls *.go | grep -v "_test.go")
grep -irnw "filepath" -ve "pattern"
or
grep -ve "pattern" < file
above command will give us the result as -v finds the inverse of the pattern being searched
The following command could help you to filter the lines which include the substring "foo".
cat file | grep -v "foo"