For example:
let mut com = std::process::Command::new("ProgramA");
com.env("ENV_1", "VALUE_1")
.arg("-a")
.arg("foo")
.arg("-b")
.arg("--argument=bar");
// Get the command line string somehow here.
com.output().unwrap();
This will spawn a process with this command line "ProgramA" -a foo -b "--argument=with space" associated with it.
Is there a way to get this back out from the com object?
It turns out Command implements Debug; this will give me the desired result:
let answer = format!("{:?}", com);
Related
I read stdin and stderr from the command-line using:
fun runCommand(vararg commands: String): Pair<String, String> {
val proc = Runtime.getRuntime().exec(commands)
val stdIn = BufferedReader(InputStreamReader(proc.inputStream))
val stdErr = BufferedReader(InputStreamReader(proc.errorStream))
val p = Pair(stdIn.use(BufferedReader::readText).trim(), stdErr.use(BufferedReader::readText).trim())
stdIn.close();
stdErr.close();
return p;
}
This gives me a Pair of <String, String> with the output of stdin and stderr.
However, no matter how I try to compare these Strings to another String, the comparison always returns false.
Things I've tried:
runCommand("nordvpn", "account").first.compareTo("You are not logged in.")
runCommand("nordvpn", "account").first == "You are not logged in."
runCommand("nordvpn", "account").first.equals("You are not logged in.")
Might this have something to do with the encoding?
Or am I just reading the output incorrectly?
Any help would be appreciated!
Thanks to #gidds' comment I was able to find that for some reason the output of the command (stdout) had "-CR SP SP CR" (- CarriageReturn Space Space CarriageReturn" prepended, which I removed with a simple String.drop(5).
Edit: After some more thinking, I assume that the aforementioned charts were responsible for making the output of the command in the terminal colored (yellow)
First time user, looking for help with a script that's been driving me crazy.
Basically, I need to create a set number of files of an exact size (512KB, 2MB, 1GB) to test a SAN. These files need to be filled with random text so that the SAN doesn't catch the nuls and does actually allocate the blocks - that's also the reason I couldn't just use fsutils.
Now, I've been messing with the new-bigrandomfile by Verboon and tweaking it to my needs.
However I'm getting the error:
You cannot call a method on a null-valued expression.
At L:\random5.ps1:34 char:9
+ $stream.Write($longstring)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
This is the bit of code I've come up with so far; I'll add a loop at the end to copy the file I just created N times so to fill up the lun.
Set-Strictmode -Version 2.0
#temp file
$file = "c:\temp\temp.rnd"
#charset size
$charset = 64
#Block Size
$blocksize = 512
#page size
$Pagesize = 512KB
#Number of blocks in a page
$blocknum = $Pagesize / $blocksize
#Resulting/desired test file size
$filesize = 1GB
#number of pages in a file
$pagenum = $filesize / $Pagesize
# create the stream writer
$stream = System.IO.StreamWriter $file
# get a 64 element Char[]; I added the - and _ to have 64 chars
[char[]]$chars = 'azertyuiopqsdfghjklmwxcvbnAZERTYUIOPQSDFGHJKLMWXCVBN0123456789-_'
1..$Pagenum | ForEach-Object {
# get a page's worth of blocks
1..$blocknum| ForEach-Object {
# randomize all chars and...
$rndChars = $chars | Get-Random -Count $chars.Count
# ...join them in a string
$string = -join $rndChars
# repeat random string N times to get a full block string length
$longstring = $string * ($blocksize / $charset)
# write 1 block to file
$stream.Write($longstring)
# release resources by clearing string variables
Clear-Variable string, longstring
}
}
$stream.Close()
$stream.Dispose()
# release resources through garbage collection
[GC]::Collect()
$file.Close()
I've tried a gazillion variants like:
$stream = [System.IO.StreamWriter] $file
$stream = System.IO.StreamWriter $file
$stream = NewObject System.IO.StreamWriter $file
Of course, being a total noob at powershell, I've tried using quotes, brackets, provided the full path instead of the variable, etc. All (or most) seem to be valid syntax variants, according to a ton of examples I found online, but the output is still the same.
In case you have any improvement to suggest or alternative way to perform this task I'm all ears.
Edited the script above: just a couple of " for $file made the error disappear, - thanks LinuxDisciple; however, the file gets created but stays at 0 bytes and the script stuck in a loop.
Fix your instantiation of StreamWriter to any of these correct variants:
$stream = [System.IO.StreamWriter]::new($file)
$stream = [IO.StreamWriter]::new($file) # the default namespace may be omitted
$stream = New-Object System.IO.StreamWriter $file
You can specify encoding:
$stream = [IO.StreamWriter]::new(
$file,
$false, # don't append
[Text.Encoding]::ASCII
)
See StreamWriter on MSDN for available constructors and parameters.
PowerShell ISE offers autocomplete with tooltips:
type [streamw and press Ctrl-Space to autocomplete the full .NET class name
type ]:: to see the available methods and properties
type new and press Ctrl-Space to see the constructor overrides
whenever needed, put the caret at the method name and press Ctrl-Space for the tooltip
I know nothing about powershell but a few things:
Are you sure $longstring has a value before you call stream.Write()? It sounds like it's null and that's why the error. If you can somehow output the value of $longstring to the console, it would help you make sure that it has a value.
Also, troubleshoot the code with a simplified version of your code, so that you can pinpoint what's going on, for example
$file = c:\temp\temp.rnd
$stream = System.IO.StreamWriter $file
$longstring = 'whatever'
$stream.Write($longstring)
I have the following Nim program:
import threadpool
var channel: TChannel[string]
proc consumer(channel: TChannel[string]) =
let (flag,msg) = tryRecv(channel)
if flag:
echo msg
channel.open()
spawn consumer(channel)
channel.send("hello")
channel.close()
sync()
When I try to compile it, it gives me this error message:
testchannels.nim(6, 27) Error: type mismatch: got (TChannel[system.string])
but expected one of:
system.tryRecv(c: var TChannel[tryRecv.TMsg])
I don't understand what the error message is trying to tell me...
Ahh, I think I got it now!
The important part of the error message was the var in system.tryRecv(c: var TChannel[tryRecv.TMsg]): tryRecv expects the channel variable to be mutable, which it wasn't in the above code.
The solution is to remove the parameter from the consume proc:
import threadpool
var channel: TChannel[string]
proc consumer() {.gcsafe.} =
if peek[string](channel) != -1:
echo recv(channel)
channel.open()
spawn consumer()
channel.send("hello")
channel.close()
sync()
I am attempting to set up a small test environment (homelab) using CentOS 6.6, Rancid 3.1, Looking Glass, and some Cisco Switches/Routers, with httpd acting as the handler. I have picked up a little perl by means of this endeavor, but python (more 2 than 3) is my background. Right now, everything on the rancid side of things works without issue: bin/clogin successfully logs into all of the equipment in the router.db file, and logging of the configs is working as expected. All switches/routers to be accessed are available and online, verified by ssh connection to devices as well as using bin/clogin.
Right now, I have placed the lg.cgi and lgform.cgi files into var/www/cgi-bin/ which allows the forms to be run as cgi scripts. I had to modify the files to split on ';' instead of ':' due to the change in the .db file in Rancid 3.1:#record = split('\:', $_); was replaced with: #record = split('\;', $_); etc. Once that change was made, I was able to load the lgform.cgi with the proper router.db parsing. At this point, it seemed like everything should be good to go. When I attempt to ping from one of those devices out to 8.8.8.8, the file correctly redirects to lg.cgi, and the page loads, but with
main is unavailable. Try again later.
as the error, where 'main' is the router hostname. Using this output, I was able to find the function responsible for this output. Here it is before I added anything:
sub DoRsh
{
my ($router, $mfg, $cmd, $arg) = #_;
my($ctime) = time();
my($val);
my($lckobj) = LockFile::Simple->make(-delay => $lock_int,
-max => $max_lock_wait, -hold => $max_lock_hold);
if ($pingcmd =~ /\d$/) {
`$pingcmd $router`;
} else {
`$pingcmd $router 56 1`;
}
if ($?) {
print "$router is unreachable. Try again later.\n";
return(-1);
}
if ($LG_SINGLE) {
if (! $lckobj->lock("$cache_dir/$router")) {
print "$router is busy. Try again later.\n";
return(-1);
}
}
$val = &DoCmd($router, $mfg, $cmd, $arg);
if ($LG_SINGLE) {
$lckobj->unlock("$cache_dir/$router");
}
return($val);
}
In order to dig in a little deeper, I peppered that function with several print statements. Here is the modified function, followed by the output from the loaded lg.cgi page:
sub DoRsh
{
my ($router, $mfg, $cmd, $arg) = #_;
my($ctime) = time();
my($val);
my($lckobj) = LockFile::Simple->make(-delay => $lock_int,
-max => $max_lock_wait, -hold => $max_lock_hold);
if ($pingcmd =~ /\d$/) {
`$pingcmd $router`;
} else {
`$pingcmd $router 56 1`;
}
print "About to test the ($?) branch.\n";
print "Also who is the remote_user?:' $remote_user'\n";
print "What about the ENV{REMOTE_USER} '$ENV{REMOTE_USER}'\n";
print "Here is the ENV{HOME}: '$ENV{HOME}'\n";
if ($?) {
print "$lckobj is the lock object.\n";
print "#_ something else to look at.\n";
print "$? whatever this is suppose to be....\n";
print "Some variables:\n";
print "$mfg is the mfg.\n";
print "$cmd was the command passed in with $arg as the argument.\n";
print "$pingcmd $router\n";
print "$cloginrc - Is the cloginrc pointing correctly?\n";
print "$LG_SINGLE the next value to be tested.\n";
print "$router is unreachable. Try again later.\n";
return(-1);
}
if ($LG_SINGLE) {
if (! $lckobj->lock("$cache_dir/$router")) {
print "$router is busy. Try again later.\n";
return(-1);
}
}
$val = &DoCmd($router, $mfg, $cmd, $arg);
if ($LG_SINGLE) {
$lckobj->unlock("$cache_dir/$router");
}
return($val);
}
OUTPUT:
About to test the (512) branch.
Also who is the remote_user?:' '
What about the ENV{REMOTE_USER} ''
Here is the ENV{HOME}: '.'
LockFile::Simple=HASH(0x1a13650) is the lock object.
main cisco ping 8.8.8.8 something else to look at.
512 whatever this is suppose to be....
Some variables:
cisco is the mfg.
ping was the command passed in with 8.8.8.8 as the argument.
/bin/ping -c 1 main
./.cloginrc - Is the cloginrc pointing correctly?
1 the next value to be tested.
main is unreachable. Try again later.
I can provide the code for when DoRsh is called, if necessary, but it looks mostly like this:&DoRsh($router, $mfg, $cmd, $arg);.
From what I can tell the '$?' special variable (or at least according to
this reference it is a special var) is returning the 512 value, which is causing that fork to test true. The problem is I don't know what that 512 means, nor where it is coming from. Using the ref site's description ("The status returned by the last pipe close, backtick (``) command, or system operator.") and the formation of the conditional tree above, I can see that it is some error of some kind, but I don't know how else to proceed with this inspection. I'm wondering if maybe it is in response to some permission issue, since the remote_user variable is null, when I didn't expect it to be. Any guidance anyone may be able to provide would be helpful. Furthermore, if there is any information that I may have skipped over, that I didn't think to include, or that may prove helpful, please ask, and I will provide to the best of my ability
May be you put in something like
my $pingret=$pingcmd ...;
print 'Ping result was:'.$pingret;
And check the returned strings?
I have some Tcl scripts that are executed by defining variables in the command-line invocation:
$ tclsh84 -cmd <script>.tcl -DEF<var1>=<value1> -DEF<var2>=<value2>
Is there a way to check if var1 and var2 are NOT defined at the command line and then assign them with a set of default values?
I tried the keywords global, variable, and set, but they all give me this error when I say "if {$<var1>==""}": "can't read <var1>: no such variable"
I'm not familiar with the -def option on tclsh.
However, to check if a variable is set, instead of using 'catch', you can also use 'info exist ':
if { ![info exists blah] } {
set blah default_value
}
Alternatively you can use something like the cmdline package from tcllib. This allows you to set up defaults for binary flags and name/value arguments, and give them descriptions so that a formatted help message can be displayed. For example, if you have a program that requires an input filename, and optionally an output filename and a binary option to compress the output, you might use something like:
package require cmdline
set sUsage "Here you put a description of what your program does"
set sOptions {
{inputfile.arg "" "Input file name - this is required"}
{outputfile.arg "out.txt" "Output file name, if not given, out.txt will be used"}
{compressoutput "0" "Binary flag to indicate whether the output file will be compressed"}
}
array set options [::cmdline::getoptions argv $sOptions $sUsage]
if {$options(inputfile) == ""} {puts "[::cmdline::usage $sOptions $sUsage]";exit}
The .arg suffix indicates this is a name/value pair argument, if that is not listed, it will assume it is a binary flag.
You can catch your command to prevent error from aborting the script.
if { [ catch { set foo $<var1> } ] } {
set <var1> defaultValue
}
(Warning: I didn't check the exact syntax with a TCL interpreter, the above script is just to give the idea).