I would like to list all plain files that are not python scripts in zsh.
Why does the following "code" not work and what is the proper solution?
ls -l *(.)~*.py
UPDATE:
I have setopt extended_glob in my .zshrc.
And
ls -ld *~*.py``
works as expected.
(I added the -d in the command to prevent directories from getting expanded).
The problem is that ~ is a glob operator (that also requires EXTENDED_GLOB be set), while (.) is a glob qualifier, which means it must be added to the end of the entire pattern, not used in the middle. Use
ls *~*.py(.)
instead. That is, *~*.py is your pattern (all files not ending in .py), and (.) is applied to the results. (Perhaps yet another way to put it is to say that glob operators can only work on unqualified patterns.)
I want to list all .c files, except .mod.c files. I use zsh 5.2 (x86_64-debian-linux-gnu) with oh-my-zsh. The pattern I use is following:
$ ls *.c
ipmi_bt_sm.c ipmi_devintf.mod.c ipmi_msghandler.c
ipmi_powernv.c ipmi_poweroff.mod.c ipmi_si.mod.c
ipmi_ssif.c ipmi_watchdog.mod.c ipmi_devintf.c
ipmi_kcs_sm.c ipmi_msghandler.mod.c ipmi_poweroff.c
ipmi_si_intf.c ipmi_smic_sm.c ipmi_watchdog.c
$ ls *.c~mod.c
zsh: no matches found: *.c~mod.c
$ ls .*.c~aoesuthaoestuhsththsh
zsh: no matches found: .*.c~aoesuthaoestuhsththsh
I'm sure that '*.c~mod.c' is correct, because this is exactly what is proposed at following web-site.
http://www.strcat.de/zsh/ :
ls *.c~lex.c matches all .c files except lex.c
Do I have to enable something specific for extended globbing? Or disable something which hinders this function?
Firstly, you need to make sure extended globbing is turned on:
setopt extended_glob
(You'll probably want that in .zshrc)
As for your pattern, what you want is *.c~*.mod.c.
The way it works is pattern1~pattern2, and it yields all the matches of pattern1, minus all the matches of pattern2. What you had was "Everything that ends in .c, minus mod.c". What you want is really "eveything that ends in .c, minus everything that ends in .mod.c", which is what I give above.
Someone accidentally created a file name '-l' and I cannot remove it, because rm -l interprets the filename as a flag. I've tried quotes, escaping and nothing is working.
In virtually all Unix commandline utilities you can use a double-dash -- to separate options from arguments. Under the hood, getopt will stop attempting to parse arguments as options when it first encounters a --. From the docs:
getopt has three ways to deal with options that follow non-options argv elements. The special argument ‘--’ forces in all cases the end of option scanning.
In your specific case with rm, use:
$ rm -- -l
In my .bash_profile I have the following lines:
PATHDIRS="
/usr/local/mysql/bin
/usr/local/share/python
/opt/local/bin
/opt/local/sbin
$HOME/bin"
for dir in $PATHDIRS
do
if [ -d $dir ]; then
export PATH=$PATH:$dir
fi
done
However I tried copying this to my .zshrc, and the $PATH is not being set.
First I put echo statements inside the "if directory exists" function and I found that the if statement was evaluating to false, even for directories that clearly existed.
Then I removed the directory-exists check, and the $PATH was being set incorrectly like this:
/usr/bin:/bin:/usr/sbin:/sbin:
/usr/local/bin
/opt/local/bin
/opt/local/sbin
/Volumes/Xshare/kburke/bin
/usr/local/Cellar/ruby/1.9.2-p290/bin
/Users/kevin/.gem/ruby/1.8/bin
/Users/kevin/bin
None of the programs in the bottom directories were being found or executed.
What am I doing wrong?
Unlike other shells, zsh does not perform word splitting or globbing after variable substitution. Thus $PATHDIRS expands to a single string containing exactly the value of the variable, and not to a list of strings containing each separate whitespace-delimited piece of the value.
Using an array is the best way to express this (not only in zsh, but also in ksh and bash).
pathdirs=(
/usr/local/mysql/bin
…
~/bin
)
for dir in $pathdirs; do
if [ -d $dir ]; then
path+=$dir
fi
done
Since you probably aren't going to refer to pathdirs later, you might as well write it inline:
for dir in \
/usr/local/mysql/bin \
… \
~/bin
; do
if [[ -d $dir ]]; then path+=$dir; fi
done
There's even a shorter way to express this: add all the directories you like to the path array, then select the ones that exist.
path+=/usr/local/mysql/bin
…
path=($^path(N))
The N glob qualifier selects only the matches that exist. Add the -/ to the qualifier list (i.e. (-/N) or (N-/)) if you're worried that one of the elements may be something other than a directory or a symbolic link to one (e.g. a broken symlink). The ^ parameter expansion flag ensures that the glob qualifier applies to each array element separately.
You can also use the N qualifier to add an element only if it exists. Note that you need globbing to happen, so path+=/usr/local/mysql/bin(N) wouldn't work.
path+=(/usr/local/bin/mysql/bin(N-/))
You can put
setopt shwordsplit
in your .zshrc. Then zsh will perform world splitting like all Bourne shells do. That the default appears to be noshwordsplit is a misfeature that causes many a head scratching. I'd be surprised if it wasn't a FAQ. Lets see... yup:
http://zsh.sourceforge.net/FAQ/zshfaq03.html#l18
3.1: Why does $var where var="foo bar" not do what I expect?
Still not sure what the problem was (maybe newlines in $PATHDIRS)? but changing to zsh array syntax fixed it:
PATHDIRS=(
/usr/local/mysql/bin
/usr/local/share/python
/usr/local/scala/scala-2.8.0.final/bin
/opt/local/Library/Frameworks/Python.framework/Versions/2.6/bin
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin
/opt/local/etc
/opt/local/bin
/opt/local/sbin
$HOME/.gem/ruby/1.8/bin
$HOME/bin)
and
path=($path $dir)
How do I grep tab (\t) in files on the Unix platform?
If using GNU grep, you can use the Perl-style regexp:
grep -P '\t' *
The trick is to use $ sign before single quotes. It also works for cut and other tools.
grep $'\t' sample.txt
I never managed to make the '\t' metacharacter work with grep.
However I found two alternate solutions:
Using <Ctrl-V> <TAB> (hitting Ctrl-V then typing tab)
Using awk: foo | awk '/\t/'
From this answer on Ask Ubuntu:
Tell grep to use the regular expressions as defined by Perl (Perl has
\t as tab):
grep -P "\t" <file name>
Use the literal tab character:
grep "^V<tab>" <filename>
Use printf to print a tab character for you:
grep "$(printf '\t')" <filename>
One way is (this is with Bash)
grep -P '\t'
-P turns on Perl regular expressions so \t will work.
As user unwind says, it may be specific to GNU grep. The alternative is to literally insert a tab in there if the shell, editor or terminal will allow it.
Another way of inserting the tab literally inside the expression is using the lesser-known $'\t' quotation in Bash:
grep $'foo\tbar' # matches eg. 'foo<tab>bar'
(Note that if you're matching for fixed strings you can use this with -F mode.)
Sometimes using variables can make the notation a bit more readable and manageable:
tab=$'\t' # `tab=$(printf '\t')` in POSIX
id='[[:digit:]]\+'
name='[[:alpha:]_][[:alnum:]_-]*'
grep "$name$tab$id" # matches eg. `bob2<tab>323`
There are basically two ways to address it:
(Recommended) Use regular expression syntax supported by grep(1). Modern grep(1) supports two forms of POSIX 1003.2 regex syntax: basic (obsolete) REs, and modern REs. Syntax is described in details on re_format(7) and regex(7) man pages which are part of BSD and Linux systems respectively. The GNU grep(1) also supports Perl-compatible REs as provided by the pcre(3) library.
In regex language the tab symbol is usually encoded by \t atom. The atom is supported by BSD extended regular expressions (egrep, grep -E on BSD compatible system), as well as Perl-compatible REs (pcregrep, GNU grep -P).
Both basic regular expressions and Linux extended REs apparently have no support for the \t. Please consult UNIX utility man page to know which regex language it supports (hence the difference between sed(1), awk(1), and pcregrep(1) regular expressions).
Therefore, on Linux:
$ grep -P '\t' FILE ...
On BSD alike system:
$ egrep '\t' FILE ...
$ grep -E '\t' FILE ...
Pass the tab character into pattern. This is straightforward when you edit a script file:
# no tabs for Python please!
grep -q ' ' *.py && exit 1
However, when working in an interactive shell you may need to rely on shell and terminal capabilities to type the proper symbol into the line. On most terminals this can be done through Ctrl+V key combination which instructs terminal to treat the next input character literally (the V is for "verbatim"):
$ grep '<Ctrl>+<V><TAB>' FILE ...
Some shells may offer advanced support for command typesetting. Such, in bash(1) words of the form $'string' are treated specially:
bash$ grep $'\t' FILE ...
Please note though, while being nice in a command line this may produce compatibility issues when the script will be moved to another platform. Also, be careful with quotes when using the specials, please consult bash(1) for details.
For Bourne shell (and not only) the same behaviour may be emulated using command substitution augmented by printf(1) to construct proper regex:
$ grep "`printf '\t'`" FILE ...
Use echo to insert the tab for you grep "$(echo -e \\t)"
grep "$(printf '\t')" worked for me on Mac OS X
A good choice is to use sed.
sed -n '/\t/p' file
Examples (works in bash, sh, ksh, csh,..):
[~]$ cat testfile
12 3
1 4 abc
xa c
a c\2
1 23
[~]$ sed -n '/\t/p' testfile
xa c
a c\2
[~]$ sed -n '/\ta\t/p' testfile
a c\2
(This answer has been edited following suggestions in comments. Thank you all)
use gawk, set the field delimiter to tab (\t) and check for number of fields. If more than 1, then there is/are tabs
awk -F"\t" 'NF>1' file
+1 way, that works in ksh, dash, etc: use printf to insert TAB:
grep "$(printf 'BEGIN\tEND')" testfile.txt
On ksh I used
grep "[^I]" testfile
The answer is simpler. Write your grep and within the quote type the tab key, it works well at least in ksh
grep " " *
Using the 'sed-as-grep' method, but replacing the tabs with a visible character of personal preference is my favourite method, as it clearly shows both which files contain the requested info, and also where it is placed within lines:
sed -n 's/\t/\*\*\*\*/g' file_name
If you wish to make use of line/file info, or other grep options, but also want to see the visible replacement for the tab character, you can achieve this by
grep -[options] -P '\t' file_name | sed 's/\t/\*\*\*\*/g'
As an example:
$ echo "A\tB\nfoo\tbar" > test
$ grep -inH -P '\t' test | sed 's/\t/\*\*\*\*/g'
test:1:A****B
test:2:foo****bar
EDIT: Obviously the above is only useful for viewing file contents to locate tabs --- if the objective is to handle tabs as part of a larger scripting session, this doesn't serve any useful purpose.
This works well for AIX. I am searching for lines containing JOINED<\t>ACTIVE
voradmin cluster status | grep JOINED$'\t'ACTIVE
vorudb201 1 MEMBER(g) JOINED ACTIVE
*vorucaf01 2 SECONDARY JOINED ACTIVE
You might want to use grep "$(echo -e '\t')"
Only requirement is echo to be capable of interpretation of backslash escapes.
These alternative binary identification methods are totally functional. And, I really like the one's using awk, as I couldn't quite remember the syntaxic use with single binary chars. However, it should also be possible to assign a shell variable a value in a POSIX portable fashion (i.e. TAB=echo "#" | tr "\100" "\011"), and then employ it from there everywhere, in a POSIX portable fashion; as well (i.e grep "$TAB" filename). While this solution works well with TAB, it will also work well other binary chars, when another desired binary value is used in the assignment (instead of the value for the TAB character to 'tr').
The $'\t' notation given in other answers is shell-specific -- it seems to work in bash and zsh but is not universal.
NOTE: The following is for the fish shell and does not work in bash:
In the fish shell, one can use an unquoted \t, for example:
grep \t foo.txt
Or one can use the hex or unicode notations e.g.:
grep \X09 foo.txt
grep \U0009 foo.txt
(these notations are useful for more esoteric characters)
Since these values must be unquoted, one can combine quoted and unquoted values by concatenation:
grep "foo"\t"bar"
You can also use a Perl one-liner instead of grep resp. grep -P:
perl -ne 'print if /\t/' FILENAME
You can type
grep \t foo
or
grep '\t' foo
to search for the tab character in the file foo. You can probably also do other escape codes, though I've only tested \n. Although it's rather time-consuming, and unclear why you would want to, in zsh you can also type the tab character, back to the begin, grep and enclose the tab with quotes.
Look for blank spaces many times [[:space:]]*
grep [[:space:]]*'.''.'
Will find something like this:
'the tab' ..
These are single quotations ('), and not double ("). This is how you make concatenation in grep. =-)