大约有 1,832 项符合查询结果（耗时：0.0252秒） [XML]
Multiple select statements in Single query
...T(*)
FROM user_table
) AS tot_user,
(
SELECT COUNT(*)
FROM cat_table
) AS tot_cat,
(
SELECT COUNT(*)
FROM course_table
) AS tot_course
share
|
improve this answer
...
Using Java to find substring of a bigger string using Regular Expression
...es.add(m.group(1));
}
return matches;
}
get_matches("FOO[BAR] FOO[CAT]", "\\[(.*?)\\]")) // returns [BAR, CAT]
share
|
improve this answer
|
follow
|...
How to wait for a keypress in R?
...
As someone already wrote in a comment, you don't have to use the cat before readline(). Simply write:
readline(prompt="Press [enter] to continue")
If you don't want to assign it to a variable and don't want a return printed in the console, wrap the readline() in an invisible():
invisib...
How to get .pem file from .key and .crt files?
How can I create a PEM file from an SSL certificate?
10 Answers
10
...
Count occurrences of a char in plain text file
...rep -o f <file> | wc -l
Note: Besides much easier to remember/duplicate and customize, this is about three times (sorry, edit! botched the first test) faster than Vereb's answer.
share
|
imp...
List submodules in a Git repository
...dule path and the URL it refers to.
For example, from root of repository, cat .gitmodules will print contents to the screen (assuming you have cat).
Because .gitmodule files have the Git configuration format, you can use git config to parse those files:
git config --file .gitmodules --name-only -...
Read lines from a file into a Bash array [duplicate]
...tabs, just newlines/CR
$ IFS=$'\r\n' GLOBIGNORE='*' command eval 'XYZ=($(cat /etc/passwd))'
$ echo "${XYZ[5]}"
sync:x:5:0:sync:/sbin:/bin/sync
Also note that you may be setting the array just fine but reading it wrong - be sure to use both double-quotes "" and braces {} as in the example above
...
Apply multiple functions to multiple groupby columns
... second half of the currently accepted answer is outdated and has two deprecations. First and most important, you can no longer pass a dictionary of dictionaries to the agg groupby method. Second, never use .ix.
If you desire to work with two separate columns at the same time I would suggest using ...
Parallelize Bash script with maximum number of processes
...k and we then want foo.jpeg and foo.out removed from the remote computer:
cat list_of_files | \
parallel --trc {.}.out -S server1,server2,: \
"my_script {} > {.}.out"
GNU Parallel makes sure the output from each job does not mix, so you can use the output as input for another program:
some-co...
Passing arguments to “make run”
...
run:
@echo ./prog $$FOO
Usage:
$ make run FOO="the dog kicked the cat"
./prog the dog kicked the cat
or:
$ FOO="the dog kicked the cat" make run
./prog the dog kicked the cat
Alternatively use the solution provided by Beta:
run:
@echo ./prog $(filter-out $@,$(MAKECMDGOALS))
%:
...