Hi all,
As seen in NetBSD, FreeBSD and Linux, script(1) could do with a way to
tell it what command to run instead of your $SHELL. This implements
the "-c command" option. I've taken the logic to start the command
(and its arguments, if any) from crontab(1), execv'ing `sh -c
<command>`.
I wrote this because I got fed up with typing `cu -l cuaU3 -s 19200`
right after starting script every time: it annoys my command line
editing fingers that I can't just recall what I did before.
There's a roundabout way of achieving something similar by setting
SHELL to some script that runs your command with its arguments, but
that's just silly (and nasty).
NetBSD: uses "-c command", executes the command using system(3)
Linux: uses "-c command", didn't look at the implementation
FreeBSD: uses arguments after the filename, wields execvp(3)
(these three have a bunch more extra options, all of which mostly look
like bullshit - specifying an alternative command seems the only
useful thing to me)
Illumos: feature parity with current OpenBSD, no -c command
My implementation worked from the get go, so there must be something
wrong with it. All comments and feedback appreciated; asbestos
underwear at the ready.
Sample output:
[weerd@pom] $ obj/script -c "ls -l" output.`date +%s`
Script started, output file is output.1513183391
total 36
drwxr-xr-x 2 weerd wsrc 512 May 9 2017 CVS
-rw-r--r-- 1 weerd wsrc 131 Sep 21 1997 Makefile
lrwxrwx--- 1 weerd wsrc 23 Dec 13 17:42 obj -> /usr/obj/usr.bin/script
-rw-r--r-- 1 weerd wsrc 0 Dec 13 17:43 output.1513183391
-rw-r--r-- 1 weerd wsrc 3642 Dec 13 17:42 script.1
-rw-r--r-- 1 weerd wsrc 8464 Dec 13 17:41 script.c
Script done, output file is output.1513183391
Paul 'WEiRD' de Weerd
Index: script.1
===================================================================
RCS file: /cvs/src/usr.bin/script/script.1,v
retrieving revision 1.14
diff -u -p -r1.14 script.1
--- script.1 15 Jan 2012 20:06:40 -0000 1.14
+++ script.1 13 Dec 2017 12:27:32 -0000
@@ -39,6 +39,7 @@
.Sh SYNOPSIS
.Nm script
.Op Fl a
+.Op Fl c Ar command
.Op Ar file
.Sh DESCRIPTION
.Nm
@@ -65,6 +66,13 @@ Append the output to
or
.Pa typescript ,
retaining the prior contents.
+.It Fl c Ar command
+Run
+.Ar command
+instead of an interactive shell.
+To run a
+.Ar command
+with its own arguments, enclose it in quotes.
.El
.Pp
The script ends when the forked shell exits (a control-D
Index: script.c
===================================================================
RCS file: /cvs/src/usr.bin/script/script.c,v
retrieving revision 1.33
diff -u -p -r1.33 script.c
--- script.c 12 Apr 2017 14:49:05 -0000 1.33
+++ script.c 13 Dec 2017 12:15:20 -0000
@@ -89,7 +89,7 @@ int istty;
__dead void done(int);
void dooutput(void);
-void doshell(void);
+void doshell(char *);
void fail(void);
void finish(int);
void scriptflush(int);
@@ -102,15 +102,20 @@ main(int argc, char *argv[])
struct sigaction sa;
struct winsize win;
char ibuf[BUFSIZ];
+ char *cmd;
ssize_t cc, off;
int aflg, ch;
+ cmd = NULL;
aflg = 0;
- while ((ch = getopt(argc, argv, "a")) != -1)
+ while ((ch = getopt(argc, argv, "ac:")) != -1)
switch(ch) {
case 'a':
aflg = 1;
break;
+ case 'c':
+ cmd = optarg;
+ break;
default:
fprintf(stderr, "usage: %s [-a] [file]\n", __progname);
exit(1);
@@ -163,7 +168,7 @@ main(int argc, char *argv[])
if (child)
dooutput();
else
- doshell();
+ doshell(cmd);
}
bzero(&sa, sizeof sa);
@@ -302,9 +307,10 @@ scriptflush(int signo)
}
void
-doshell(void)
+doshell(char *cmd)
{
char *shell;
+ char *argp[] = {"sh", "-c", NULL, NULL};
shell = getenv("SHELL");
if (shell == NULL)
@@ -313,8 +319,15 @@ doshell(void)
(void)close(master);
(void)fclose(fscript);
login_tty(slave);
- execl(shell, shell, "-i", (char *)NULL);
- warn("%s", shell);
+
+ if (cmd != NULL) {
+ argp[2] = cmd;
+ execv(_PATH_BSHELL, argp);
+ warn("unable to execute %s", _PATH_BSHELL);
+ } else {
+ execl(shell, shell, "-i", (char *)NULL);
+ warn("%s", shell);
+ }
fail();
}
--
>++++++++[<++++++++++>-]<+++++++.>+++[<------>-]<.>+++[<+
+++++++++++>-]<.>++[<------------>-]<+.--------------.[-]
http://www.weirdnet.nl/
