Command fails if I use variable instead of string constant

**qazwart** · Jul 19 '07, 04:05 PM

Re: Command fails if I use variable instead of string constant

Okay, we figured this one out. When I did a "trim" on the $cvs_module
variable, the problem cleared up. I was reading the $cvs_module from a
file, and apparently, I didn't remove the "\n" from the end of the
variable when I extracted the information I wanted. Because I was
looking at it via a web page, the "\n" didn't show up.

On Jul 18, 6:26 pm, qazwart <qazw...@gmail. comwrote:

I am reading from a "cvs rlog" command, and I need both the STDOUT and
STDERR. Unfortunately, something very strange is happening. If I do
this:
>
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label neo 2>&1"; //
Hard coded module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");
>
I get the combined STDOUT and STDERR in my while loop. However if I do
this:
>
$cvs_module = "neo"
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label $cvs_module
2>&1"; //Use variable for module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");
>
I don't get STDERR in my while loop.
>
Note the "DEBUG" line. This is a little routine I wrote to help me see
what is going on. Here is the output of the DEBUG line in the first
code example:
>
DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {
>
Here is the output of the "DEBUG" line in the second code example:
>
DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {
>
Is there something I should be looking for?

**ZeldorBlat** · Jul 19 '07, 04:35 PM

Re: Command fails if I use variable instead of string constant

On Jul 18, 6:26 pm, qazwart <qazw...@gmail. comwrote:

I am reading from a "cvs rlog" command, and I need both the STDOUT and
STDERR. Unfortunately, something very strange is happening. If I do
this:
>
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label neo 2>&1"; //
Hard coded module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");
>
I get the combined STDOUT and STDERR in my while loop. However if I do
this:
>
$cvs_module = "neo"
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label $cvs_module
2>&1"; //Use variable for module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");
>
I don't get STDERR in my while loop.
>
Note the "DEBUG" line. This is a little routine I wrote to help me see
what is going on. Here is the output of the DEBUG line in the first
code example:
>
DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {
>
Here is the output of the "DEBUG" line in the second code example:
>
DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {
>
Is there something I should be looking for?

Before running the command echo out the value of $cmd to make sure it
is what you think it is.

**petersprc** · Jul 19 '07, 06:45 PM

Re: Command fails if I use variable instead of string constant

It shouldn't make a difference. Try setting error_reporting (E_ALL) to
see if you have any errors.

Missing a semi-colon here?

$cvs_module = "neo"

On Jul 18, 6:26 pm, qazwart <qazw...@gmail. comwrote:

I am reading from a "cvs rlog" command, and I need both the STDOUT and
STDERR. Unfortunately, something very strange is happening. If I do
this:
>
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label neo 2>&1"; //
Hard coded module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");
>
I get the combined STDOUT and STDERR in my while loop. However if I do
this:
>
$cvs_module = "neo"
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label $cvs_module
2>&1"; //Use variable for module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");
>
I don't get STDERR in my while loop.
>
Note the "DEBUG" line. This is a little routine I wrote to help me see
what is going on. Here is the output of the DEBUG line in the first
code example:
>
DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {
>
Here is the output of the "DEBUG" line in the second code example:
>
DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {
>
Is there something I should be looking for?

**qazwart** · Jul 22 '07, 02:15 AM

Re: Command fails if I use variable instead of string constant

On Jul 19, 12:33 pm, ZeldorBlat <zeldorb...@gma il.comwrote:

Before running the command echo out the value of $cmd to make sure it
is what you think it is.

That's what I did with the "DEBUG" line. Here it is printing out from
my code when "neo" is hard coded:

DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {

And, here is the second example when "neo" was read in from a
variable:

DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {

See the difference? Neither did I. If I did this in Perl on a
terminal, I'd see the NL, but in HTML, NLs and multiple spaces aren't
normally displayed in the browser.

I had a colleague recommend that I print out the value of
"$cvs_modul e", and I had put quotes around it. That displayed as:

DEBUG: $cvs_module = "neo "

The "space" on the end clued me in that this might be an issue, and
sure enough, when I "trimmed" $cvs_module, the program worked.

I did learn one lesson: My "DEBUG" function needs to surround the
output with <pre></pretags. That way, I would have seen the NL in
the output.

On Jul 18, 6:26 pm, qazwart <qazw...@gmail. comwrote:
>
>
>

I am reading from a "cvs rlog" command, and I need both the STDOUT and
STDERR. Unfortunately, something very strange is happening. If I do
this:

>

$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label neo 2>&1"; //
Hard coded module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");

>

I get the combined STDOUT and STDERR in my while loop. However if I do
this:

>

$cvs_module = "neo"
$cmd = "$cvs_cmd -q rlog -NS -r$from_label::$ to_label $cvs_module
2>&1"; //Use variable for module
DEBUG ("if (!($cvs_fh = popen(\"$cmd\", 'r'))) {");
if (!($cvs_fh = popen("$cmd", 'r'))) {
generate_error( "Canot open command \"$cmd\" for reading");
}
$exam_file_flag = false;
$inside_revisio n_flag = false;
$inside_comment _flag = false;
print "Generating Initial Release Information: ";
flush();
while($line = fgets($cvs_fh)) {
DEBUG ("....line = \"$line\"");

>

I don't get STDERR in my while loop.

>

Note the "DEBUG" line. This is a little routine I wrote to help me see
what is going on. Here is the output of the DEBUG line in the first
code example:

>

DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {

>

Here is the output of the "DEBUG" line in the second code example:

>

DEBUG: if (!( = popen("/usr/local/bin/cvs -d :pserver:build@ aladdin:/
tools/CVSROOT -q rlog -NS -rNEO-199::NEO-210 neo 2>&1", 'r'))) {

>

Is there something I should be looking for?

>
Before running the command echo out the value of $cmd to make sure it
is what you think it is.

**Toby A Inkster** · Jul 22 '07, 11:05 AM

Re: Command fails if I use variable instead of string constant

qazwart wrote:

I did learn one lesson: My "DEBUG" function needs to surround the
output with <pre></pretags. That way, I would have seen the NL in
the output.

Your browser's "View Source" capability should have clued you in too.

--
Toby A Inkster BSc (Hons) ARCS
[Geek of HTML/SQL/Perl/PHP/Python/Apache/Linux]
[OS: Linux 2.6.12-12mdksmp, up 31 days, 13:59.]

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http://tobyinkster.co.uk/blog/2007/07/20/html-table-parsing/

Command fails if I use variable instead of string constant

Command fails if I use variable instead of string constant

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