The Thompson goto command was bizarre because it was not a shell built-in. It was actually an external command. Decisions like this were made to get the thing to run in a 16 bit machine.
First of all the label concept was piggy-backed onto the colon command. It is a command that does nothing. It still exists today in bash and ksh. I hope you have heard of it. You can give the colon command arguments which the shell "processes" but the command itself ignores. This was used to make the colon command a form of comment. The leading number-sign comment had not yet appeared. A comment like this:
was harmful because the shell would try to send the colon command's output to /etc/passwd. You had to be sure that your comments had no side effects. You could put the : command anywhere you want. The shell would know it should do nothing.
But a colon command used as label had additional restrictions becuase it had to be processed by /bin/goto. There were various versions of /bin/goto. Your label had to match whatever rules your version of /bin/goto had. The goto command used some magic to reposition the shell's input file. This means the input file has to be seekable. A file on paper tape is an example of a non-seekable file. A file on a deck of cards is another example.
The alternate syntax you have a seen "label:" is what csh uses.
Warning: I don't use goto's so maybe some of this is wrong.
LINK:
Unix Manual (man page) pages in HTML
http://www.rt.com/man/
: More then 100 Commands found on a Unix system mannual pages can be obtained/refered here. Good Link.. (1 Reply)
Hi
Does anyone know were to go (web link please?) to learn the BACIS of UNIX in OS X, I would like to know a little more about unix (for the apple) but seem to get lost in all the wen sites, and idealy find a site where i could download a manual for the unix shell in OS X.
Any ideas? (4 Replies)
Is there a Unix (Solaris v8 ksh) version of the old basic command gosub or goto? I've researched the return command, but can't identify the command to return from. I am not trying to return from a function. Can someone give me a basic understanding of this please? Thanks so much in advance for... (3 Replies)
1) Can a script be made to ignore all signals.
2) Does the parent process always picks up the exit status of its children.
3) Can one program give rise to multiple processes.
4) Is a file is synonymous with a process.
5) Is the kill command only used to kill a running process. (1 Reply)
hi guys...
am new 2 dis unix world...
am in need of a unix manual...
cud sum1 pls post sum links 2 download it?>?>? :confused:
Danks in advance... ;) ;) ;) (1 Reply)
Hi,I'm currently working on an dev environment that has no jobs to run the scripts.How can I manual run the scripts. on Unix?
---------- Post updated at 05:45 AM ---------- Previous update was at 05:43 AM ----------
Is it something like this....
../int/inbound>./filename.sh inputfilename
... (5 Replies)
my code does somthing like this:
#!bin/ksh
sqlplus / | While read id
do
temp=`echo $id`
i = i+1
done
j=0
while
do
--connecting to sql and executing a Stored proc for 1st id
--checking for the status
status = $?
if
error
--need to... (1 Reply)
Hi,
echo "yes or no?"
read ans
case $ans in
*)
echo "yes"
;;
*)
echo "no"
;;
*)
echo "yes or no only"
#here, if the answer is not "Y" or "N", I want to go back to asking "yes or no?" (9 Replies)
Well, guys I saw a question about GOTO for Python.
So this gave me the inspiration to attempt a GOTO function for 'dash', (bash and ksh too).
Machine: MBP OSX 10.14.3, default bash terminal, calling '#!/usr/local/bin/dash'...
This is purely a fun project to see if it is possible in PURE... (3 Replies)