* [9fans] wctl @ 2023-05-09 3:31 有澤健治 2023-05-09 6:11 ` umbraticus 0 siblings, 1 reply; 6+ messages in thread From: 有澤健治 @ 2023-05-09 3:31 UTC (permalink / raw) To: Fans of the OS Plan 9 from Bell Labs [-- Attachment #1: Type: text/plain, Size: 1307 bytes --] Hello, 9fans In writing a program I met a problem on finding window size. cat /dev/wctl shows something like this: hebe% cat /dev/wctl 456 91 1214 603 current visible hebe% Need DEL key to stop. I want to get this info without manual intervention. I tried a experimental code: #include <u.h> #include <libc.h> void main(void) { char buf[256]; int fd,n; fd = open("/dev/wctl",OREAD); print("%d\n",fd); //n = readn(fd,buf,1);//NG. buffer too small //n = readn(fd,buf,48);//NG. truncated //n = readn(fd,buf,56);//NG. truncated //n = readn(fd,buf,70);//NG. truncated n = readn(fd,buf,71);//OK, n=71 //n = readn(fd,buf,111);//OK. n=71 //n = readn(fd,buf,117);//OK. n=71 //n = readn(fd,buf,128);//NG. hungup /* I donn't know the reasnalbe value m for readn(fd,buf,m) */ if(n < 0){ print("%r\n"); } buf[n] = 0; print("n=%d\n%s\n",n,buf); close(fd); exits(nil); } I don't know whether m in readn(fd,buf,m) depends on something or not. If depends. then how to know getting OK value? Kenji Arisawa ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tf13f657beb7b12c0-M60ccbc9ae01219d2e2f46c4f Delivery options: https://9fans.topicbox.com/groups/9fans/subscription [-- Attachment #2: Type: text/html, Size: 2141 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] wctl 2023-05-09 3:31 [9fans] wctl 有澤健治 @ 2023-05-09 6:11 ` umbraticus 2023-05-09 7:59 ` Richard Miller 0 siblings, 1 reply; 6+ messages in thread From: umbraticus @ 2023-05-09 6:11 UTC (permalink / raw) To: 9fans ; read -c 72 /dev/wctl rio(4) umbraticus ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tf13f657beb7b12c0-Ma0337129de0681f834f7e7c7 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] wctl 2023-05-09 6:11 ` umbraticus @ 2023-05-09 7:59 ` Richard Miller 2023-05-09 13:01 ` 有澤健治 0 siblings, 1 reply; 6+ messages in thread From: Richard Miller @ 2023-05-09 7:59 UTC (permalink / raw) To: 9fans > ; read -c 72 /dev/wctl Or, if your chosen flavour of Plan 9 doesn't have the 'read -c' option, one of these will do: dd -if /dev/wctl -bs 72 -count 1 -quiet 1 syscall -o read 0 buf 72 </dev/wctl >[2]/dev/null ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tf13f657beb7b12c0-Mdd9f3de6c6653fc343ffc333 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] wctl 2023-05-09 7:59 ` Richard Miller @ 2023-05-09 13:01 ` 有澤健治 2023-05-09 15:04 ` sirjofri 0 siblings, 1 reply; 6+ messages in thread From: 有澤健治 @ 2023-05-09 13:01 UTC (permalink / raw) To: 9fans [-- Attachment #1: Type: text/plain, Size: 698 bytes --] Thanks for umbraticus and Richard. The value 72 is experimentally OK. However I am not convinced yet. I can't find the value in the manual. Kenji Arisawa 2023年5月9日(火) 17:00 Richard Miller <9fans@hamnavoe.com>: > > ; read -c 72 /dev/wctl > > Or, if your chosen flavour of Plan 9 doesn't have the 'read -c' > option, one of these will do: > > dd -if /dev/wctl -bs 72 -count 1 -quiet 1 > syscall -o read 0 buf 72 </dev/wctl >[2]/dev/null > ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tf13f657beb7b12c0-M429a1a214f0fb13d9c461eda Delivery options: https://9fans.topicbox.com/groups/9fans/subscription [-- Attachment #2: Type: text/html, Size: 1995 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] wctl 2023-05-09 13:01 ` 有澤健治 @ 2023-05-09 15:04 ` sirjofri 2023-05-09 21:17 ` 有澤健治 0 siblings, 1 reply; 6+ messages in thread From: sirjofri @ 2023-05-09 15:04 UTC (permalink / raw) To: 9fans 09.05.2023 15:04:07 有澤健治 <karisawa@gmail.com>: > Thanks for umbraticus and Richard. > > The value 72 is experimentally OK. > However I am not convinced yet. > I can't find the value in the manual. Not experimentally. According to rio(4), it's 4 values padded to 12 chars, plus the window state as two strings, also padded to 12. If you do the math: 6*12=72. sirjofri ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tf13f657beb7b12c0-M653f4f77683fc542820c5944 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] wctl 2023-05-09 15:04 ` sirjofri @ 2023-05-09 21:17 ` 有澤健治 0 siblings, 0 replies; 6+ messages in thread From: 有澤健治 @ 2023-05-09 21:17 UTC (permalink / raw) To: 9fans [-- Attachment #1: Type: text/plain, Size: 838 bytes --] Thanks. sirjofri OK. I have understood! I have misunderstood the meaning "padded". Sorry for may poor english. 2023年5月10日(水) 0:06 sirjofri <sirjofri+ml-9fans@sirjofri.de>: > > 09.05.2023 15:04:07 有澤健治 <karisawa@gmail.com>: > > > Thanks for umbraticus and Richard. > > > > The value 72 is experimentally OK. > > However I am not convinced yet. > > I can't find the value in the manual. > > Not experimentally. According to rio(4), it's 4 values padded to 12 chars, > plus the window state as two strings, also padded to 12. If you do the > math: 6*12=72. > > sirjofri ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tf13f657beb7b12c0-M43294eac9d9b73dec4e91cc7 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription [-- Attachment #2: Type: text/html, Size: 2241 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-05-09 21:17 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-05-09 3:31 [9fans] wctl 有澤健治 2023-05-09 6:11 ` umbraticus 2023-05-09 7:59 ` Richard Miller 2023-05-09 13:01 ` 有澤健治 2023-05-09 15:04 ` sirjofri 2023-05-09 21:17 ` 有澤健治
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