another newbie in Linux shell scripting.
Basically I've a folder with many files in it. But I need to get only the files that ends with ".log"
Below is my version which doesn't work
#!/bin/sh
for i in *;
do
if [ "$i" == "$i".log ]; then
echo $i;
fi
done
Could someone please help me on this ? Thanks a lot !
Any reason you can't you can't just do it like this?
for fname in *.log
do
echo $fname
done
#John3136 has the simplest answer. With bash, you would use the fact that == inside [[ ... ]] is actually a pattern matching operator, not an equality operator:
#!/bin/bash
for f in *; do
if [[ "$f" == *.log ]]; then
echo "$f"
fi
done
See http://www.gnu.org/software/bash/manual/bashref.html#Conditional-Constructs
Related
sorry for that odd title. I didn't know how to word it the right way.
I'm trying to write a script to filter my wiki files to those got directories with the same name and the ones without. I'll elaborate further.
here is my file system:
what I need to do is print a list of those files which have directories in their name and another one of those without.
So my ultimate goal is getting:
with dirs:
Docs
Eng
Python
RHEL
To_do_list
articals
without dirs:
orphan.txt
orphan2.txt
orphan3.txt
I managed to get those files with dirs. Here is me code:
getname () {
file=$( basename "$1" )
file2=${file%%.*}
echo $file2
}
for d in Mywiki/* ; do
if [[ -f $d ]]; then
file=$(getname $d)
for x in Mywiki/* ; do
dir=$(getname $x)
if [[ -d $x ]] && [ $dir == $file ]; then
echo $dir
fi
done
fi
done
but stuck with getting those without. if this is the wrong way of doing this please clarify the right one.
any help appreciated. Thanks.
Here's a quick attempt.
for file in Mywiki/*.txt; do
nodir=${file##*/}
test -d "${file%.txt}" && printf "%s\n" "$nodir" >&3 || printf "%s\n" "$nodir"
done >with 3>without
This shamelessly uses standard output for the non-orphans. Maybe more robustly open another separate file descriptor for that.
Also notice how everything needs to be quoted unless you specifically require the shell to do whitespace tokenization and wildcard expansion on the value of a token. Here's the scoop on that.
That may not be the most efficient way of doing it, but you could take all files, remove the extension, and the check if there isn't a directory with that name.
Like this (untested code):
for file in Mywiki/* ; do
if [ -f "$d" ]; then
dirname=$(getname "$d")
if [ ! -d "Mywiki/$dirname" ]; then
echo "$file"
fi
fi
done
To List all the files in current dir
list1=`ls -p | grep -v /`
To List all the files in current dir without extension
list2=`ls -p | grep -v / | sed 's/\.[a-z]*//g'`
To List all the directories in current dir
list3=`ls -d */ | sed -e "s/\///g"`
Now you can get the desired directory listing using intersection of list2 and list3. Intersection of two lists in Bash
Hello from a Linux Bash newbie!
I have a list.txt containing a list of files which I want to copy to a destination($2). These are unique images but some of them have the same filename.
My plan is to loop through each line in the text file, with the copy to the destination occurring when the file is not there, and a mv rename happening when it is present.
The problem I am having is creating the pathname to check the file against. In the code below, I am taking the filename only from the pathname, and I want to add that to the destination ($2) with the "/" in between to check the file against.
When I run the program below I get "Permission Denied" at line 9 which is where I try and create the path.
for line in $(cat list.txt)
do
file=$[ basename $line ]
path=$[ $2$file ]
echo $path
if [ ! -f $path ];
then
echo cp $line $2
else
echo mv $line.DUPLICATE $2
fi
done
I am new to this so appreciate I may be missing something obvious but if anyone can offer any advice it would be much appreciated!
Submitting this since OP is new in BASH scripting no good answer has been posted yet.
DESTINATION="$2"
while read -r line; do
file="${line##*/}"
path="$2/$file"
[[ ! -f $path ]] && cp "$line" "$path" || mv "$line" "$path.DUP"
done < list.txt
Don't have logic for counting duplicates at present to keep things simple. (Which means code will take care of one dup entry) As an alternative you get uniq from list.txt beforehand to avoid the duplicate situation.
#anubhava: Your script looks good. Here is a small addition to it to work with several dupes.
It adds a numer to the $path.DUP name
UniqueMove()
{
COUNT=0
while [ -f "$1" ]
do
(( COUNT++ ))
mv -n "$1" "$2$COUNT"
done
}
while read -r line; do
file="${line##*/}"
path="$2/$file"
[[ ! -f $path ]] && cp "$line" "$path" || UniqueMove "$line" "$path.DUP"
done < list.txt
I can see an individual file's permissions with ls -l.
In the case where there are hundreds or thousands of files in a directory - most of which I can't read, how do I check which files I have permission to read?
Try that :
for i in *; do test -r "$i" && echo "$i is readable for $USER"; done
See help test
You can also do (bash test) :
for i in *; do [[ -r "$i" ]] && echo "$i is readable for $USER"; done
See man bash | less +/'\[\[ expression'
Or with POSIX shell :
for i in *; do [ -r "$i" ] && echo "$i is readable for $USER"; done
See help [
Finally
&& is a shortcut (boolean AND) for if condition; then action; fi
You can use stat(1) to discover file permissions.
I hope someone can help me out. For the past month or so I have be learning the Bash... I have a program ( a simple language study program ) that I want to be able to install and run from a script.
I have a script that will create a new folder and move itself into it. The way I am doing it at the moment is below, although I have had problems with arrays that I am using later. I was wondering if there was a cleaner way of getting the new path to file name. Any help or insight would be greatly appreciated.
#!/bin/bash
echo "# path to me ---------------> ${0} "
echo "# parent path --------------> ${0%/*} "
echo "# my name ------------------> ${0##*/} "
if [[ ! -d ${0%/*}/SomeNewFolder ]] && [[ ! -d ${0%/*}/../SomeNewFolder ]]
then
mkdir ${0%/*}/SomeNewFolder
mv ${0} ${0%/*}/SomeNewFolder/${0##*/}
fi
echo ${0%/*}
newpath=$(echo "${0%/*}/SomeNewFolder")
echo $newpath
All the best, Ben
exit
For clarity, I would probably declare named variables for your common values instead of constantly reusing the ${0} array. It's also good practice to quote variables and strings.
The only major issue I saw, was running ./script.sh would make $0 equal just the filename, so I add "./" to the beginning in that case.
#!/bin/bash -u
ME="${0}"
if [[ ! "$ME" =~ /^\// ]]; then
ME="./$ME"
fi
PARENT="${ME%/*}"
FILENAME="${ME##*/}"
FOLDER="SomeNewFolder"
NEW="$PARENT/$FOLDER"
if [[ ! -d "$NEW" ]] && [[ "${PARENT%/*}" != "$FOLDER" ]]; then
mkdir "$NEW"
mv "$ME" "$NEW"
fi
echo "$PARENT"
echo "$NEW"
Well, you could do something like this to get an absolute path:
PARENTPATH=$( cd "$( dirname "$0" )" && pwd )
NEWPATH=${PARENTPATH}/SomeNewFolder
me="$0"
newdir=SomeNewFolder
if [[ $me =~ ^/ ]] ; then
full_path="$me"
else
full_path="$PWD/$me"
fi
full_path="${full_path//\/\.\///}" # prettify
path_to_me="${full_path%/*}"
parent_dir="${path_to_me##*/}"
if [ ! "$parent_dir" = "$newdir" ] ; then
mkdir -p "$path_to_me/$newdir"
mv -f "$full_path" "$path_to_me/$newdir/"
fi
Basically similar to what lunixbochs was doing, but with a few minor alterations
lower case variable names so as not to be confused with environment variables
crudely estimates absolute path
-f and -p becuase interactivity is never cool, and why not
Installing and setting up programs is more appropriately done from a make file. Granted, it seems intimidating at first, but the basics, such as what you want, are quite simple. For your project, you would ideally have three item:
your program
your run script
your makefile i.e. your installer
This breaks apart each of these different components, making each of them easier to manage. If you tar them together, you can move the tar file to a new computer and reinstall without any changes. Bash is a wonderful tool, but an installer it is not.
Sample make script below:
.PHONY: all clean
SCRIPT=yourScriptName.sh
SUBFOLDER=someFolder
all: $(SCRIPT)
$(SCRIPT): $(SUBFOLDER)
cp $(SCRIPT) $(SUBFOLDER)
$(SUBFOLDER):
mkdir $(SUBFOLDER)
clean:
-rm -f $(SUBFOLDER)/$(SCRIPT)
-rmdir $(SUBFOLDER)
IMPORTANT! make is whitespace sensitive! Those indents are tabs not four spaces.
As arguments to my script there are some file paths. Those can, of course, be relative (or contain ~). But for the functions I've written I need paths that are absolute, but do not have their symlinks resolved.
Is there any function for this?
MY_PATH=$(readlink -f $YOUR_ARG) will resolve relative paths like "./" and "../"
Consider this as well (source):
#!/bin/bash
dir_resolve()
{
cd "$1" 2>/dev/null || return $? # cd to desired directory; if fail, quell any error messages but return exit status
echo "`pwd -P`" # output full, link-resolved path
}
# sample usage
if abs_path="`dir_resolve \"$1\"`"
then
echo "$1 resolves to $abs_path"
echo pwd: `pwd` # function forks subshell, so working directory outside function is not affected
else
echo "Could not reach $1"
fi
http://www.linuxquestions.org/questions/programming-9/bash-script-return-full-path-and-filename-680368/page3.html has the following
function abspath {
if [[ -d "$1" ]]
then
pushd "$1" >/dev/null
pwd
popd >/dev/null
elif [[ -e "$1" ]]
then
pushd "$(dirname "$1")" >/dev/null
echo "$(pwd)/$(basename "$1")"
popd >/dev/null
else
echo "$1" does not exist! >&2
return 127
fi
}
which uses pushd/popd to get into a state where pwd is useful.
Simple one-liner:
function abs_path {
(cd "$(dirname '$1')" &>/dev/null && printf "%s/%s" "$PWD" "${1##*/}")
}
Usage:
function do_something {
local file=$(abs_path $1)
printf "Absolute path to %s: %s\n" "$1" "$file"
}
do_something $HOME/path/to/some\ where
I am still trying to figure out how I can get it to be completely oblivious to whether the path exists or not (so it can be used when creating files as well).
This does the trick for me on OS X: $(cd SOME_DIRECTORY 2> /dev/null && pwd -P)
It should work anywhere. The other solutions seemed too complicated.
If your OS supports it, use:
realpath -s "./some/dir"
And using it in a variable:
some_path="$(realpath -s "./some/dir")"
Which will expand your path. Tested on Ubuntu and CentOS, might not be available on yours. Some recommend readlink, but documentation for readlink says:
Note realpath(1) is the preferred command to use for canonicalization functionality.
In case people wonder why I quote my variables, it's to preserve spaces in paths. Like doing realpath some path will give you two different path results. But realpath "some path" will return one. Quoted parameters ftw :)
Thanks to NyanPasu64 for the heads up. You'll want to add -s if you don't want it to follow the symlinks.
Use readlink -f <relative-path>, e.g.
export FULLPATH=`readlink -f ./`
Maybe this is more readable and does not use a subshell and does not change the current dir:
dir_resolve() {
local dir=`dirname "$1"`
local file=`basename "$1"`
pushd "$dir" &>/dev/null || return $? # On error, return error code
echo "`pwd -P`/$file" # output full, link-resolved path with filename
popd &> /dev/null
}
on OS X you can use
stat -f "%N" YOUR_PATH
on linux you might have realpath executable. if not, the following might work (not only for links):
readlink -c YOUR_PATH
There's another method. You can use python embedding in bash script to resolve a relative path.
abs_path=$(python3 - <<END
from pathlib import Path
path = str(Path("$1").expanduser().resolve())
print(path)
END
)
self edit, I just noticed the OP said he's not looking for symlinks resolved:
"But for the functions I've written I need paths that are absolute, but do not have their symlinks resolved."
So guess this isn't so apropos to his question after all. :)
Since I've run into this many times over the years, and this time around I needed a pure bash portable version that I could use on OSX and linux, I went ahead and wrote one:
The living version lives here:
https://github.com/keen99/shell-functions/tree/master/resolve_path
but for the sake of SO, here's the current version (I feel it's well tested..but I'm open to feedback!)
Might not be difficult to make it work for plain bourne shell (sh), but I didn't try...I like $FUNCNAME too much. :)
#!/bin/bash
resolve_path() {
#I'm bash only, please!
# usage: resolve_path <a file or directory>
# follows symlinks and relative paths, returns a full real path
#
local owd="$PWD"
#echo "$FUNCNAME for $1" >&2
local opath="$1"
local npath=""
local obase=$(basename "$opath")
local odir=$(dirname "$opath")
if [[ -L "$opath" ]]
then
#it's a link.
#file or directory, we want to cd into it's dir
cd $odir
#then extract where the link points.
npath=$(readlink "$obase")
#have to -L BEFORE we -f, because -f includes -L :(
if [[ -L $npath ]]
then
#the link points to another symlink, so go follow that.
resolve_path "$npath"
#and finish out early, we're done.
return $?
#done
elif [[ -f $npath ]]
#the link points to a file.
then
#get the dir for the new file
nbase=$(basename $npath)
npath=$(dirname $npath)
cd "$npath"
ndir=$(pwd -P)
retval=0
#done
elif [[ -d $npath ]]
then
#the link points to a directory.
cd "$npath"
ndir=$(pwd -P)
retval=0
#done
else
echo "$FUNCNAME: ERROR: unknown condition inside link!!" >&2
echo "opath [[ $opath ]]" >&2
echo "npath [[ $npath ]]" >&2
return 1
fi
else
if ! [[ -e "$opath" ]]
then
echo "$FUNCNAME: $opath: No such file or directory" >&2
return 1
#and break early
elif [[ -d "$opath" ]]
then
cd "$opath"
ndir=$(pwd -P)
retval=0
#done
elif [[ -f "$opath" ]]
then
cd $odir
ndir=$(pwd -P)
nbase=$(basename "$opath")
retval=0
#done
else
echo "$FUNCNAME: ERROR: unknown condition outside link!!" >&2
echo "opath [[ $opath ]]" >&2
return 1
fi
fi
#now assemble our output
echo -n "$ndir"
if [[ "x${nbase:=}" != "x" ]]
then
echo "/$nbase"
else
echo
fi
#now return to where we were
cd "$owd"
return $retval
}
here's a classic example, thanks to brew:
%% ls -l `which mvn`
lrwxr-xr-x 1 draistrick 502 29 Dec 17 10:50 /usr/local/bin/mvn# -> ../Cellar/maven/3.2.3/bin/mvn
use this function and it will return the -real- path:
%% cat test.sh
#!/bin/bash
. resolve_path.inc
echo
echo "relative symlinked path:"
which mvn
echo
echo "and the real path:"
resolve_path `which mvn`
%% test.sh
relative symlinked path:
/usr/local/bin/mvn
and the real path:
/usr/local/Cellar/maven/3.2.3/libexec/bin/mvn
Do you have to use bash exclusively? I needed to do this and got fed up with differences between Linux and OS X. So I used PHP for a quick and dirty solution.
#!/usr/bin/php <-- or wherever
<?php
{
if($argc!=2)
exit();
$fname=$argv[1];
if(!file_exists($fname))
exit();
echo realpath($fname)."\n";
}
?>
I know it's not a very elegant solution but it does work.