大约有 36,000 项符合查询结果（耗时：0.0441秒） [XML]
Retrieving the output of subprocess.call() [duplicate]
...tdout, and/or stdin parameters and read from the pipes by using the communicate() method:
from subprocess import Popen, PIPE
p = Popen(['program', 'arg1'], stdin=PIPE, stdout=PIPE, stderr=PIPE)
output, err = p.communicate(b"input data that is passed to subprocess' stdin")
rc = p.returncode
The r...
Using sed, how do you print the first 'N' characters of a line?
...
colrm x
For example, if you need the first 100 characters:
cat file |colrm 101
It's been around for years and is in most linux's and bsd's (freebsd for sure), usually by default. I can't remember ever having to type apt-get install colrm.
...
How do I restrict a float value to only two places after the decimal point in C?
...ree different rounding rules you might want to choose: round down (ie, truncate after two decimal places), rounded to nearest, and round up. Usually, you want round to nearest.
As several others have pointed out, due to the quirks of floating point representation, these rounded values may not be e...
find: missing argument to -exec
...nd line, so it might be split up) with all filenames. See this example:
$ cat /tmp/echoargs
#!/bin/sh
echo $1 - $2 - $3
$ find /tmp/foo -exec /tmp/echoargs {} \;
/tmp/foo - -
/tmp/foo/one - -
/tmp/foo/two - -
$ find /tmp/foo -exec /tmp/echoargs {} +
/tmp/foo - /tmp/foo/one - /tmp/foo/two
Your com...
How to specify more spaces for the delimiter using cut?
... the third field and every field after it, omitting the first two fields"
cat log | tr -s [:blank:] |cut -d' ' -f 3-
I do not believe there is an equivalent command for awk or perl split where we do not know how many fields there will be, ie out put the 3rd field through field X.
...
Counting occurrences in Vim without marking the buffer changed
...
:!cat %| grep -c "pattern"
It's not exactly vim command, but it will give you what you need from vim.
You can map it to the command if you need to use it frequently.
...
See line breaks and carriage returns in editor
... file, for running a list of commands.
Edit your .vimrc file, like this :
cat >> ~/.vimrc <<EOF
set ffs=unix
set encoding=utf-8
set fileencoding=utf-8
set listchars=eol:¶
set list
EOF
When you're executing vim, the commands into .vimrc are executed, and you can see this example :
My...
Breaking loop when “warnings()” appear in R
...onverted from warnings.
j <- function() {
for (i in 1:3) {
cat(i, "\n")
as.numeric(c("1", "NA"))
}}
# warn = 0 (default) -- warnings as warnings!
j()
# 1
# 2
# 3
# Warning messages:
# 1: NAs introduced by coercion
# 2: NAs introduced by coercion
# 3: NAs introduced by c...
RSpec controller testing - blank response.body
...uestion), it occurred to me that there are different ways to skin the same cat. In other words, rather than checking for the body text, you might be able to check the content of the flash.
response.body.should =~ /Invalid email or password/
might be an equivalent check to:
flash[:alert].should...
Change the image source on rollover using jQuery
...aming convention.
HTML
<img data-other-src="big-zebra.jpg" src="small-cat.jpg">
<img data-other-src="huge-elephant.jpg" src="white-mouse.jpg">
<img data-other-src="friendly-bear.jpg" src="penguin.jpg">
JavaScript
$('img').bind('mouseenter mouseleave', function() {
$(this)....