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I have a directory with lots of PDFs that have spaces in their file names.
file 1.pdf
file 2.pdf
file 3.pdf
# And so on
I ran this command in that directory.
pdftk `ls -v` cat output combined-report.pdf
But the terminal spat out a bunch of errors like this.
Error: Unable to find file.
Error: Failed to open PDF file:
file
Error: Unable to find file.
Error: Failed to open PDF file:
1.pdf
How do I combine the PDFs using pdftk or any other package in Arch Linux? To clarify, I want to combine the files in the order printed by ls -v
Just use a wildcard while creating combining the pdfs like:
pdftk *.pdf cat output newfile.pdf
Or else you could use something like this:
pdftk file\ 1.pdf file\ 2.pdf cat output newfile.pdf
Try this:
find . -name 'file*.pdf' -print0 | sort -z -V | xargs -0 -I{} pdftk {} cat output combined-report.pdf
or this:
ls -v file*.pdf | xargs -d'\n' -I{} pdftk {} cat output combined-report.pdf
In the first line, "-print0", "-z", and "-0" tell the corresponding command to use null as delimiter. The "-V" parameter for sort specifies "version sort" which I think should produce the sorting you wanted. Normally, the parameters that are piped are appended to the end of xargs. "-I{}" specifies a placeholder, "{}", that you can use to put them in the middle of the command.
The second line is similar, except that it takes parameter from "ls", and use newline '\n' as delimiter.
Note: there are potential problems with using "ls". See the link posted by #stephen-p.
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I am a new bee to bash scripting. while studying Advanced bash scripting I came across this command. I'm not understand how the command is working and what is the use of curly braces. Thanks in advance.
Your command:
ls . | xargs -i -t cp ./{} $1
could be divided into the following parts:
ls .
List the current directory (this will list all the files/directories but the hidden ones)
| xargs -i -t cp ./{} $1
Basically the xargs breaks the piped output (ls in this case) and provides each element in the list as input to the following command (cp in this case). The -t option is to show in the stderr what xargs is actually executing. The -i is used for string replacement. In this case since nothing has been provided it will substitute the {} by the input. $1 is the name of the destination where your files will be copied (I guess in this case it should be a directory for the command to make sense otherwise you will be copying all the files to the same destination).
So for example, if you have lets say a directory that has files called a, b, c. When you run this command it will perform the following:
cp ./a $1
cp ./b $1
cp ./c $1
NOTE:
The -i option is deprecated, -I (uppercase i) should be used instead
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I have this script I'm studying and I would like to know what is cat doing in this section.
if cat downloaded.txt | grep "$count" >/dev/null
then
echo "File already downloaded!"
else
echo $count >> downloaded.txt
cat $count | egrep -o "http://server.*(png|jpg|gif)" | nice -n -20 wget --no-dns-cache -4 --tries=2 --keep-session-cookies --load-cookies=cookies.txt --referer=http://server.com/wallpaper/$number -i -
rm $count
fi
Like most cats, this is a useless cat.
Instead of:
if cat downloaded.txt | grep "$count" >/dev/null
It could have been written:
if grep "$count" download.txt > /dev/null
In fact, because you've eliminated the pipe, you've eliminated issues with which exit value the if statement is dealing with.
Most Unix cats you'll see are of the useless variety. However, people like cats almost as much as they like using a grep/awk pipe, or using multiple grep or sed commands instead of combining everything into a single command.
The cat command stands for concatenate which is to allow you to concatenate files. It was created to be used with the split command which splits a file into multiple parts. This was useful if you had a really big file, but had to put it on floppy drives that couldn't hold the entire file:
split -b140K -a4 my_really_big_file.txt my_smaller_files.txt.
Now, I'll have my_smaller_files.txt.aaaa and my_smaller_files.txt.aaab and so forth. I can put them on the floppies, and then on the other computer. (Heck, I might go all high tech and use UUCP on you!).
Once I get my files on the other computer, I can do this:
cat my_smaller_files.txt.* > my_really_big_file.txt
And, that's one cat that isn't useless.
cat prints out the contents of the file with the given name (to the standard output or to wherever it's redirected). The result can be piped to some other command (in this case, (e)grep to find something in the file contents). Concretely, here it tries to download the images referenced in that file, then adds the name of the file to downloaded.txt in order to not process it again (this is what the check in if was about).
http://www.linfo.org/cat.html
"cat" is a unix command that reads the contents of one or more files sequentially and by default prints out the information the user console ("stdout" or standard output).
In this case cat is being used to read the contents of the file "downloaded.txt", the pipe "|" is redirecting/feeding its output to the grep program, which is searching for whatever is in the variable "$count" to be matched with.
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I am currently working on a C project that contains over 50 .h and .c files. I would like to know if there is a quick way to search for certain lines of code (like ctrl+f for a window for example) without having to actually search each file one by one.
Thank you in advance
On Linux/Unix there's a command line tool called grep you can use it to search multiple files for a string. For examples if I wanted to search for strcpy in all files:
~/sandbox$ grep -rs "strcpy"*
test.c: strcpy(OSDMenu.name,"OSD MENU");
-r gives searches recursivly so you get all the files in all directories (from the current one) searched. -s ignores warnings, in case you run into non-readable files.
Now if you wanted to search for something custom, and you can't remember the case there's options like -i to allow for case insenstive searches.
~/sandbox$ grep -rsi "myint" *
test.c: int myInt = 5;
test.c: int MYINT = 10;
You can also use regular expressions in case you forgot exactly what you were looking for was called (indeed the name, 'grep' comes from the sed command g/re/p -- global/regular expression/print:
~/sandbox$ grep -rsi "my.*" *
test.c: int myInt = 5;
test.c: int MYINT = 10;
test.c: float myfloat = 10.9;
install cygwin if you aren't using *nix and use find/grep, e.g.
find . -name '*\.[ch]' | xargs grep -n 'myfuncname'
In fact, I made this a little script findinsrc that can be called with findinsrc path1, [path2, ...] pattern. The central line, after checking arguments etc, is
find "${#:1:$#-1}" -type f \( -iname '*.c' -o -iname '*.cpp' -o -iname '*.h' -o -iname '*.hpp' \) -print0 | xargs -0 grep -in "${#:$#}"
"${#:1:$#-1}" are the positional parameters 1 .. n-1, that is, the path(s), supplied as the starting points for find. "${#:$#}" is the last parameter, the pattern supplied to grep.
the -o "option" to find is a logical OR combining the search criteria; because the "default" combination of options is AND, all the ORs must be parenthesized for correct evaluation. Because parentheses have special meaning to the shell, they must be escaped so that they are passed through to find as command line arguments.
-print0 instructs find to separate its output items not with a newline or space but with a null character which cannot appear in path names; this way, there is a clear distinction between whitespace in a path ("My Pictures" nonsense) and separation between paths.
-iname is a case insensitive search, in case files are ending in .CPP etc.
xargs -0 is there specifically to digest find -print0 output: xargs will separate arguments read from stdin at null bytes, not at whitespace.
grep -in: -i instructs grep to perform a case insensitive search (which suits my bad memory and is catered exactly to this "find the bloody function no matter the capitalization you know what I mean" use case). The -n prints the line number, in addition to the file name, where the match occurred.
I have similar scripts findinmake, whre the find pattern includes regular Makefiles, CMakeLists.txt and a proprietary file name; and findinscripts that looks through bat, cmd and sh files. That seemed easier than introducing options to a generic script.
You can use grep to search through the files using the terminal/command line.
grep -R "string_to_search" .
-R to be recursive, search in all sub directories too
Then string you want
Then is the location, . for the current directory
On windows you can use findstr which will find files that contain strings that either exactly match or regular expression match the specified string / pattern.
findstr /?
from the command line will give you the usage. It can also recurse subdirectories (/s).
If you're using a text editor and the shell, then you can use shell tools like grep.
grep -R "some pattern" directory
However you should consider using an IDE such as Eclipse (it's not just for Java), Netbeans (there is a C plugin) or KDevelop. IDEs have keyboard shortcuts for things like "find everywhere the highlighted function is called".
Or of course there's Emacs...
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So, in linux, I have a folder with lots of big text files.
I want to delete all the lines of these files that contain a specific keyword.
Is there any easy way to do that across all files?
There already many similar answers. I'd like to add that if you want to match this is a line containing a keyword but not this is a line containing someoneelseskeyword, then you had better added brackets around the word:
sed -i '/\<keyword\>/d' *.txt
I cannot test this right now, but it should get you started
find /path/to/folder -type f -exec sed -i '/foo/d' {} ';'
find files in the directory /path/to/folder
find lines in these files containing foo
delete those lines from those files
Sure:
for x in files*
do
grep -v your_pattern "$x" > x && mv x "$x"
done
try this:
find your_path_filename |xargs sed -i '/key_word/d'
sed -i '/keyword/d' *.txt -- run this in your directory.
sed - stream editor , use it here for deleting lines in individual files
-i option : to make the changes permenent in the input files
'/keywprd/' : specifies the pattern or the key to be searched in the files
option d : informs sed that matching lines need to be deleted.
*.txt : simply tells sed to use all the text files in the directory as input for
processing , you can specify a individual or a extension like *.txt the way i did.
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How can I use grep to show just file-names (no in-line matches) on Linux?
I am usually using something like:
find . -iname "*php" -exec grep -H myString {} \;
How can I just get the file-names (with paths), but without the matches? Do I have to use xargs? I didn't see a way to do this on my grep man page.
The standard option grep -l (that is a lowercase L) could do this.
From the Unix standard:
-l
(The letter ell.) Write only the names of files containing selected
lines to standard output. Pathnames are written once per file searched.
If the standard input is searched, a pathname of (standard input) will
be written, in the POSIX locale. In other locales, standard input may be
replaced by something more appropriate in those locales.
You also do not need -H in this case.
From the grep(1) man page:
-l, --files-with-matches
Suppress normal output; instead print the name of each input
file from which output would normally have been printed. The
scanning will stop on the first match. (-l is specified by
POSIX.)
For a simple file search, you could use grep's -l and -r options:
grep -rl "mystring"
All the search is done by grep. Of course, if you need to select files on some other parameter, find is the correct solution:
find . -iname "*.php" -execdir grep -l "mystring" {} +
The execdir option builds each grep command per each directory, and concatenates filenames into only one command (+).