nz@wucs.UUCP (Neal Ziring) (04/06/85)
Description:
The script(1) command is a very convenient utility that
takes a log of the i/o to a terminal. It is incredibly
useful in an academic environment. Unfortunately,
script was written to be a quick-and-dirty logger, and
has no nice bells and whistles (like VMS PHOTO or PHOTO
on TOPS20 or rlogin(1) on BSD Unix).
The diffs below are enhancements to script, giving it
a set of tilde escapes, similar to those supported
by rlogin(1) and Mail(1).
Repeat-by:
Just go into your favorite editor while in script, and
then look at the log file. Also, try suspending the
shell script runs for you, then look at a `ps -cx'
and see what processes are running and which are stopped.
Fix:
Script runs three processed to accomplish its job:
- master, uses one pty
- slave, uses another pty
- shell, runs the SHELL for you
The changes below are primarily changes to the routines
used by the master, and a few changes to the slave.
The following is a rcs diff of the original script.c
versus the results of my hacking. If you apply patch(n)
to it, you too will be able to enjoy these enhancements.
Also, the ~. escape is a sure cure for hung script processes.
15a16,18
> #define BUFFERSIZE 64
> #define ESCCHAR '~'
>
24c27,39
< int finish();
---
> int finish(), toggle();
> char logging;
> char cmdchar = ESCCHAR ;
> char *help[] = {
> "-----------",
> "Tilde escapes are:",
> "~. terminate this script session",
> "~^Z suspend this script session",
> "~l turn data logging on/off",
> "~? get this message",
> "~~ a single tilde",
> "-----------",
> NULL };
33a49,50
> int masterpid, slavepid, shellpid; /* process ids of parts of script */
>
68a86,87
> masterpid = getpid();
> logging = 1;
80c99,101
< if (f)
---
> else shellpid = f;
> if (f) {
> (void) signal(SIGHUP, toggle);
82c103,104
< else
---
> }
> else
84a107
> slavepid = child;
90c113,115
< char ibuf[BUFSIZ];
---
> int escstart1, escstart2, esccont, linestart;
> char cur;
> char readchar();
94,95c119,190
< while ((cc = read(0, ibuf, BUFSIZ)) > 0)
< (void) write(master, ibuf, cc);
---
> for(escstart1=escstart2=esccont=0;
> (cur = readchar()) != EOF; ) {
> if (cur == '\n' || cur == '\015') {
> escstart1++;
> if (escstart2) write(master, &cmdchar, 1);
> if (esccont) esccont = 0;
> escstart2 = 0;
> }
> else if (cur == cmdchar && escstart1) {
> write(1,&cur,1);
> escstart2++; escstart1 = 0;
> continue;
> }
> else if (escstart2) {
> int i;
> esccont++;
> escstart2 = 0;
> switch (cur & 0177) {
> case '.':
> case '\04' :
> write(1,".\015\n",3);
> fflush(fscript);
> fclose(fscript);
> fail();
> break;
> case 'a':
> case 'l':
> toggle();
> kill(slavepid,SIGHUP);
> write(1,&cur,1);
> break;
> case ESCCHAR:
> write(master,&cur,1);
> escstart1=escstart2=esccont=0;
> break;
> case '?':
> write(1,&cur,1);
> for(i=0; help[i] != NULL; i++) {
> write(1,"\015\n",2);
> write(1,help[i],strlen(help[i]));
> }
> write(1,"\015\n",2);
> write(1,"\nLogging is ",12);
> write(1,( (logging)?("on \n"):("off\n") ),4);
> write(1,"\015\n",2);
> write(master,"\n",1);
> escstart1 = 1;
> escstart2=esccont=0;
> break;
> case '\032':
> write(1,"^Z\015\n",4);
> ioctl(0, TIOCSETP, (char *)&b);
> stopall();
> fixtty();
> escstart1=escstart2=esccont=0;
> break;
> default:
> write(master,&cmdchar,1);
> write(master,&cur,1);
> escstart1=escstart2=esccont=0;
> break;
> }
> continue;
> }
> else if (esccont) {
> write(1,&cur,1);
> continue;
> }
> else escstart1 = 0;
>
> (void) write(master, &cur, 1);
> }
98a194,207
> char readchar()
> {
> static char buf[BUFSIZ];
> static int nextchar = 0;
> static int charcnt = 0;
> if (nextchar >= charcnt) {
> if ( (charcnt = read(0, buf, BUFSIZ)) < 0) return (EOF);
> nextchar = 0;
> }
> return ( buf[nextchar++] );
> }
>
>
>
113c222
< char obuf[BUFSIZ];
---
> char obuf[BUFFERSIZE];
124c233,234
< (void) fwrite(obuf, 1, cc, fscript);
---
> if (logging)
> (void) fwrite(obuf, 1, cc, fscript);
221a332,343
>
> toggle()
> {
> logging = (logging) ? 0 : 1 ;
> }
>
> stopall()
> {
> kill(0, SIGTSTP); /* stop pg, I don't know if this will work. */
> kill(0, SIGCONT);
> }
>
--
========
...nz (ECL - we're here to provide superior computing)
Washington University Engineering Computer Laboratory
old style: ... ihnp4!wucs!nz
new style: nz@wucs.UUCP