I am unable to do this - I used to use a variation of the following
command to get a date that is a few hours back:

TZ=GMT+6 date '+%y%m%d%H%M'

But I think this has its limits - what is the best way I can get a
date that is x number of days back?

Thanks,
Anoop

Anoop <anoopkumarv@gmail.com> writes:
>I am unable to do this - I used to use a variation of the following
>command to get a date that is a few hours back:

>TZ=GMT+6 date '+%y%m%d%H%M'

>But I think this has its limits - what is the best way I can get a
>date that is x number of days back?

Use GNU date..

If you absolutely must use something only pre-installed, then you'll
have to write a perl/C/C++/whatever program to do the same thing GNU
date already has written.

In article <485a93f3$0$52555$8046368a@newsreader.iphouse.net> ,
Doug McIntyre <merlyn@geeks.org> wrote:

> Anoop <anoopkumarv@gmail.com> writes:
> >I am unable to do this - I used to use a variation of the following
> >command to get a date that is a few hours back:
>
> >TZ=GMT+6 date '+%y%m%d%H%M'
>
> >But I think this has its limits - what is the best way I can get a
> >date that is x number of days back?
>
> Use GNU date..
>
> If you absolutely must use something only pre-installed, then you'll
> have to write a perl/C/C++/whatever program to do the same thing GNU
> date already has written.

And if you aren't allowed to write code or scripts on the machine,
there's always that wonderful thing called a calendar. Banks used to
give them away.

--
DeeDee, don't press that button! DeeDee! NO! Dee...
[I filter all Goggle Groups posts, so any reply may be automatically by ignored]

On Jun 19, 2:34 pm, Michael Vilain <vil...@NOspamcop.net> wrote:
> In article <485a93f3$0$52555$80463...@newsreader.iphouse.net> ,
> Doug McIntyre <mer...@geeks.org> wrote:
>
> > Anoop <anoopkum...@gmail.com> writes:
> > >I am unable to do this - I used to use a variation of the following
> > >command to get a date that is a few hours back:
>
> > >TZ=GMT+6 date '+%y%m%d%H%M'
>
> > >But I think this has its limits - what is the best way I can get a
> > >date that is x number of days back?
>
> > Use GNU date..
>
> > If you absolutely must use something only pre-installed, then you'll
> > have to write a perl/C/C++/whatever program to do the same thing GNU
> > date already has written.
>
> And if you aren't allowed to write code or scripts on the machine,
> there's always that wonderful thing called a calendar. Banks used to
> give them away.
>
> --
> DeeDee, don't press that button! DeeDee! NO! Dee...
> [I filter all Goggle Groups posts, so any reply may be automatically by ignored]

OK - at the risk of being flamed as off-topic, can someone please help
me with a perl command that gives me the date that is 30 days back?

Thanks.

Anoop wrote:
> OK - at the risk of being flamed as off-topic, can someone please help
> me with a perl command that gives me the date that is 30 days back?

heard of google?

http://www.itworld.com/nl/unix_insider/05062004/

On 2008-06-19 19:51:25 +0100, Anoop <anoopkumarv@gmail.com> said:

> OK - at the risk of being flamed as off-topic, can someone please help
> me with a perl command that gives me the date that is 30 days back?

perl -e 'print scalar(localtime(time-30*24*60*60)),"\n"'

Cheers,

Chris

On Jun 19, 3:31 pm, Chris Ridd <chrisr...@mac.com> wrote:
> On 2008-06-19 19:51:25 +0100, Anoop <anoopkum...@gmail.com> said:
>
> > OK - at the risk of being flamed as off-topic, can someone please help
> > me with a perl command that gives me the date that is 30 days back?
>
> perl -e 'print scalar(localtime(time-30*24*60*60)),"\n"'
>
> Cheers,
>
> Chris

Thanks a lot for the help.

I finally ended up using a c program that someone had written [Link:
http://groups.google.com/group/comp....f0c8348ef3ef1d
]

I created the file dateback.c with the content:

#include <time.h>
#include <stdio.h>

#define ONEDAY (60*60*24)
#define DEFAULT_FORMAT "%d-%b-%Y"

int main(int argc,char *argv[])
{
time_t now;
char *date_format=NULL;
struct tm *now_s;
int daysback;
char stamp[80];

if (argc < 2 || argc > 3)
{
fprintf(stderr,"usage: daysback <number of days>
[\"<date format>\"]\n");
exit(2);
}

daysback=atoi(argv[1]);

if (argc==3)
{
date_format=(char *)malloc(strlen(argv[2]));
strcpy(date_format,argv[2]);
}
else if (getenv("DAYSBACK"))
date_format=(char *)getenv("DAYSBACK");

if ((!date_format) || (*date_format=='\0'))
{
date_format=(char *)malloc(strlen(DEFAULT_FORMAT));
strcpy(date_format,DEFAULT_FORMAT);
}

now=time(0)-daysback*ONEDAY;
now_s=localtime(&now);

strftime(stamp,80,date_format,now_s);
puts(stamp);

return(0);

}

Then I could compile this using: cc backdate.c
This created the output: a.out.
Renamed the a.out file to backdate.
Now I could include the backdate just as any command in my shell
scripts and it worked perfectly.

thanks again,
Anoop

Hi,

Anoop wrote:
> On Jun 19, 3:31 pm, Chris Ridd <chrisr...@mac.com> wrote:
>> On 2008-06-19 19:51:25 +0100, Anoop <anoopkum...@gmail.com> said:
>>
>>> OK - at the risk of being flamed as off-topic, can someone please help
>>> me with a perl command that gives me the date that is 30 days back?
>> perl -e 'print scalar(localtime(time-30*24*60*60)),"\n"'
>>
>> Cheers,
>>
>> Chris
>
> Thanks a lot for the help.
>
> I finally ended up using a c program that someone had written [Link:
> http://groups.google.com/group/comp....f0c8348ef3ef1d
> ]
>
> I created the file dateback.c with the content:
>
> #include <time.h>
> #include <stdio.h>
>
> #define ONEDAY (60*60*24)
> #define DEFAULT_FORMAT "%d-%b-%Y"
>
> int main(int argc,char *argv[])
> {
> time_t now;
> char *date_format=NULL;
> struct tm *now_s;
> int daysback;
> char stamp[80];
>
> if (argc < 2 || argc > 3)
> {
> fprintf(stderr,"usage: daysback <number of days>
> [\"<date format>\"]\n");
> exit(2);
> }
>
> daysback=atoi(argv[1]);
>
> if (argc==3)
> {
> date_format=(char *)malloc(strlen(argv[2]));
> strcpy(date_format,argv[2]);
> }
> else if (getenv("DAYSBACK"))
> date_format=(char *)getenv("DAYSBACK");
>
> if ((!date_format) || (*date_format=='\0'))
> {
> date_format=(char *)malloc(strlen(DEFAULT_FORMAT));
> strcpy(date_format,DEFAULT_FORMAT);
> }
>
> now=time(0)-daysback*ONEDAY;
> now_s=localtime(&now);
>
> strftime(stamp,80,date_format,now_s);
> puts(stamp);
>
> return(0);
>
> }
>
> Then I could compile this using: cc backdate.c
> This created the output: a.out.
> Renamed the a.out file to backdate.
> Now I could include the backdate just as any command in my shell
> scripts and it worked perfectly.
>
> thanks again,
> Anoop
Just wounder, why did you use c code compared to the nice perl script?

speed?

/michael

On 2008-06-20 00:59:15 +0100, Anoop <anoopkumarv@gmail.com> said:

> On Jun 19, 3:31 pm, Chris Ridd <chrisr...@mac.com> wrote:
>> On 2008-06-19 19:51:25 +0100, Anoop <anoopkum...@gmail.com> said:
>>
>>> OK - at the risk of being flamed as off-topic, can someone please help
>>> me with a perl command that gives me the date that is 30 days back?
>>
>> perl -e 'print scalar(localtime(time-30*24*60*60)),"\n"'
>>
>> Cheers,
>>
>> Chris
>
> Thanks a lot for the help.
>
> I finally ended up using a c program that someone had written [Link:
> http://groups.google.com/group/comp....f0c8348ef3ef1d
> ]
>
> I created the file dateback.c with the content:

You do have a couple of buffer overflows in this code. Fixes are inline below:

>
> #include <time.h>
> #include <stdio.h>
>
> #define ONEDAY (60*60*24)
> #define DEFAULT_FORMAT "%d-%b-%Y"
>
> int main(int argc,char *argv[])
> {
> time_t now;
> char *date_format=NULL;
> struct tm *now_s;
> int daysback;
> char stamp[80];
>
> if (argc < 2 || argc > 3)
> {
> fprintf(stderr,"usage: daysback <number of days>
> [\"<date format>\"]\n");
> exit(2);
> }
>
> daysback=atoi(argv[1]);
>
> if (argc==3)
> {
> date_format=(char *)malloc(strlen(argv[2]));

date_format=(char *)malloc(strlen(argv[2])+1);

> strcpy(date_format,argv[2]);
> }
> else if (getenv("DAYSBACK"))
> date_format=(char *)getenv("DAYSBACK");
>
> if ((!date_format) || (*date_format=='\0'))
> {
> date_format=(char *)malloc(strlen(DEFAULT_FORMAT));

date_format=(char *)malloc(strlen(DEFAULT_FORMAT)+1);

> strcpy(date_format,DEFAULT_FORMAT);
> }
>
> now=time(0)-daysback*ONEDAY;
> now_s=localtime(&now);
>
> strftime(stamp,80,date_format,now_s);
> puts(stamp);
>
> return(0);
>
> }

You're leaking the things you're mallocing too, but that doesn't matter
in something this small.

Cheers,

Chris

More fixes in-line.

Chris Ridd wrote:
> On 2008-06-20 00:59:15 +0100, Anoop <anoopkumarv@gmail.com> said:
>
>> On Jun 19, 3:31 pm, Chris Ridd <chrisr...@mac.com> wrote:
>>> On 2008-06-19 19:51:25 +0100, Anoop <anoopkum...@gmail.com> said:
>>>
>>>> OK - at the risk of being flamed as off-topic, can someone please help
>>>> me with a perl command that gives me the date that is 30 days back?
>>>
>>> perl -e 'print scalar(localtime(time-30*24*60*60)),"\n"'
>>>
>>> Cheers,
>>>
>>> Chris
>>
>> Thanks a lot for the help.
>>
>> I finally ended up using a c program that someone had written [Link:
>> http://groups.google.com/group/comp....f0c8348ef3ef1d
>> ]
>>
>> I created the file dateback.c with the content:
>
> You do have a couple of buffer overflows in this code. Fixes are inline
> below:
>
>>
>> #include <time.h>
>> #include <stdio.h>
#include <stdlib.h>
>>
>> #define ONEDAY (60*60*24)
>> #define DEFAULT_FORMAT "%d-%b-%Y"
>>
>> int main(int argc,char *argv[])
>> {
>> time_t now;
>> char *date_format=NULL;
>> struct tm *now_s;
>> int daysback;
>> char stamp[80];
>>
>> if (argc < 2 || argc > 3)
>> {
>> fprintf(stderr,"usage: daysback <number of days>
>> [\"<date format>\"]\n");
>> exit(2);
>> }
>>
>> daysback=atoi(argv[1]);
>>
>> if (argc==3)
>> {
>> date_format=(char *)malloc(strlen(argv[2]));
>
> date_format=(char *)malloc(strlen(argv[2])+1);
date_format = malloc(strlen(argv[2])+1);
>
>> strcpy(date_format,argv[2]);
>> }
>> else if (getenv("DAYSBACK"))
>> date_format=(char *)getenv("DAYSBACK");
>>
>> if ((!date_format) || (*date_format=='\0'))
>> {
>> date_format=(char *)malloc(strlen(DEFAULT_FORMAT));
>
> date_format=(char *)malloc(strlen(DEFAULT_FORMAT)+1);
date_format = malloc(strlen(DEFAULT_FORMAT)+1);
>
>> strcpy(date_format,DEFAULT_FORMAT);
>> }
>>
>> now=time(0)-daysback*ONEDAY;
>> now_s=localtime(&now);
>>
>> strftime(stamp,80,date_format,now_s);
>> puts(stamp);
>>
>> return(0);
>>
>> }
>
> You're leaking the things you're mallocing too, but that doesn't matter
> in something this small.
>
Don't cast the return values of malloc/calloc/realloc in C code. Ever.

Cheers,
Gary B-)