4.3BSD/usr/src/ucb/dbx/library.c
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
static char sccsid[] = "@(#)library.c 5.1 (Berkeley) 5/31/85";
#endif not lint
static char rcsid[] = "$Header: library.c,v 1.5 84/12/26 10:39:52 linton Exp $";
/*
* General purpose routines.
*/
#include <stdio.h>
#include <errno.h>
#include <signal.h>
#define public
#define private static
#define and &&
#define or ||
#define not !
#define ord(enumcon) ((int) enumcon)
#define nil(type) ((type) 0)
typedef int integer;
typedef enum { FALSE, TRUE } boolean;
typedef char *String;
typedef FILE *File;
typedef String Filename;
#undef FILE
String cmdname; /* name of command for error messages */
Filename errfilename; /* current file associated with error */
short errlineno; /* line number associated with error */
/*
* Definitions for doing memory allocation.
*/
extern char *malloc();
#define alloc(n, type) ((type *) malloc((unsigned) (n) * sizeof(type)))
#define dispose(p) { free((char *) p); p = 0; }
/*
* Macros for doing freads + fwrites.
*/
#define get(fp, var) fread((char *) &(var), sizeof(var), 1, fp)
#define put(fp, var) fwrite((char *) &(var), sizeof(var), 1, fp)
/*
* String definitions.
*/
extern String strcpy(), index(), rindex();
extern int strlen();
#define strdup(s) strcpy(malloc((unsigned) strlen(s) + 1), s)
#define streq(s1, s2) (strcmp(s1, s2) == 0)
typedef int INTFUNC();
typedef struct {
INTFUNC *func;
} ERRINFO;
#define ERR_IGNORE ((INTFUNC *) 0)
#define ERR_CATCH ((INTFUNC *) 1)
/*
* Call a program.
*
* Four entries:
*
* call, callv - call a program and wait for it, returning status
* back, backv - call a program and don't wait, returning process id
*
* The command's standard input and output are passed as FILE's.
*/
#define MAXNARGS 1000 /* unchecked upper limit on max num of arguments */
#define BADEXEC 127 /* exec fails */
#define ischild(pid) ((pid) == 0)
/* VARARGS3 */
public int call(name, in, out, args)
String name;
File in;
File out;
String args;
{
String *ap, *argp;
String argv[MAXNARGS];
argp = &argv[0];
*argp++ = name;
ap = &args;
while (*ap != nil(String)) {
*argp++ = *ap++;
}
*argp = nil(String);
return callv(name, in, out, argv);
}
/* VARARGS3 */
public int back(name, in, out, args)
String name;
File in;
File out;
String args;
{
String *ap, *argp;
String argv[MAXNARGS];
argp = &argv[0];
*argp++ = name;
ap = &args;
while (*ap != nil(String)) {
*argp++ = *ap++;
}
*argp = nil(String);
return backv(name, in, out, argv);
}
public int callv(name, in, out, argv)
String name;
File in;
File out;
String *argv;
{
int pid, status;
pid = backv(name, in, out, argv);
pwait(pid, &status);
return status;
}
public int backv(name, in, out, argv)
String name;
File in;
File out;
String *argv;
{
int pid;
fflush(stdout);
if (ischild(pid = fork())) {
fswap(0, fileno(in));
fswap(1, fileno(out));
onsyserr(EACCES, ERR_IGNORE);
execvp(name, argv);
_exit(BADEXEC);
}
return pid;
}
/*
* Swap file numbers so as to redirect standard input and output.
*/
private fswap(oldfd, newfd)
int oldfd;
int newfd;
{
if (oldfd != newfd) {
close(oldfd);
dup(newfd);
close(newfd);
}
}
/*
* Invoke a shell on a command line.
*/
#define DEF_SHELL "csh"
public shell(s)
String s;
{
extern String getenv();
String sh;
if ((sh = getenv("SHELL")) == nil(String)) {
sh = DEF_SHELL;
}
if (s != nil(String) and *s != '\0') {
call(sh, stdin, stdout, "-c", s, 0);
} else {
call(sh, stdin, stdout, 0);
}
}
/*
* Wait for a process the right way. We wait for a particular
* process and if any others come along in between, we remember them
* in case they are eventually waited for.
*
* This routine is not very efficient when the number of processes
* to be remembered is large.
*
* To deal with a kernel idiosyncrasy, we keep a list on the side
* of "traced" processes, and do not notice them when waiting for
* another process.
*/
typedef struct pidlist {
int pid;
int status;
struct pidlist *next;
} Pidlist;
private Pidlist *pidlist, *ptrclist, *pfind();
public ptraced(pid)
int pid;
{
Pidlist *p;
p = alloc(1, Pidlist);
p->pid = pid;
p->next = ptrclist;
ptrclist = p;
}
public unptraced(pid)
int pid;
{
register Pidlist *p, *prev;
prev = nil(Pidlist *);
p = ptrclist;
while (p != nil(Pidlist *) and p->pid != pid) {
prev = p;
p = p->next;
}
if (p != nil(Pidlist *)) {
if (prev == nil(Pidlist *)) {
ptrclist = p->next;
} else {
prev->next = p->next;
}
dispose(p);
}
}
private boolean isptraced(pid)
int pid;
{
register Pidlist *p;
p = ptrclist;
while (p != nil(Pidlist *) and p->pid != pid) {
p = p->next;
}
return (boolean) (p != nil(Pidlist *));
}
public pwait(pid, statusp)
int pid, *statusp;
{
Pidlist *p;
int pnum, status;
p = pfind(pid);
if (p != nil(Pidlist *)) {
*statusp = p->status;
dispose(p);
} else {
pnum = wait(&status);
while (pnum != pid and pnum >= 0) {
if (not isptraced(pnum)) {
p = alloc(1, Pidlist);
p->pid = pnum;
p->status = status;
p->next = pidlist;
pidlist = p;
}
pnum = wait(&status);
}
if (pnum < 0) {
p = pfind(pid);
if (p == nil(Pidlist *)) {
panic("pwait: pid %d not found", pid);
}
*statusp = p->status;
dispose(p);
} else {
*statusp = status;
}
}
}
/*
* Look for the given process id on the pidlist.
*
* Unlink it from list if found.
*/
private Pidlist *pfind(pid)
int pid;
{
register Pidlist *p, *prev;
prev = nil(Pidlist *);
for (p = pidlist; p != nil(Pidlist *); p = p->next) {
if (p->pid == pid) {
break;
}
prev = p;
}
if (p != nil(Pidlist *)) {
if (prev == nil(Pidlist *)) {
pidlist = p->next;
} else {
prev->next = p->next;
}
}
return p;
}
/*
* System call error handler.
*
* The syserr routine is called when a system call is about to
* set the c-bit to report an error. Certain errors are caught
* and cause the process to print a message and immediately exit.
*/
extern int sys_nerr;
extern char *sys_errlist[];
/*
* Before calling syserr, the integer errno is set to contain the
* number of the error. The routine "_mycerror" is a dummy which
* is used to force the loader to get my version of cerror rather
* than the usual one.
*/
extern int errno;
extern _mycerror();
/*
* Initialize error information, setting defaults for handling errors.
*/
private ERRINFO *errinfo;
private initErrInfo ()
{
integer i;
errinfo = alloc(sys_nerr, ERRINFO);
for (i = 0; i < sys_nerr; i++) {
errinfo[i].func = ERR_CATCH;
}
errinfo[0].func = ERR_IGNORE;
errinfo[EPERM].func = ERR_IGNORE;
errinfo[ENOENT].func = ERR_IGNORE;
errinfo[ESRCH].func = ERR_IGNORE;
errinfo[EBADF].func = ERR_IGNORE;
errinfo[ENOTTY].func = ERR_IGNORE;
errinfo[EOPNOTSUPP].func = ERR_IGNORE;
}
public syserr()
{
ERRINFO *e;
if (errno < 0 or errno > sys_nerr) {
fatal("errno %d", errno);
} else {
if (errinfo == nil(ERRINFO *)) {
initErrInfo();
}
e = &(errinfo[errno]);
if (e->func == ERR_CATCH) {
fatal(sys_errlist[errno]);
} else if (e->func != ERR_IGNORE) {
(*e->func)();
}
}
}
/*
* Catcherrs' purpose is to initialize the errinfo table, get this module
* loaded, and make sure my cerror is loaded (only applicable when this is
* in a library).
*/
public catcherrs()
{
_mycerror();
initErrInfo();
}
/*
* Turn off the error catching mechanism completely by having all errors
* ignored. This is most useful between a fork and an exec.
*/
public nocatcherrs()
{
integer i;
for (i = 0; i < sys_nerr; i++) {
errinfo[i].func = ERR_IGNORE;
}
}
/*
* Change the action on receipt of an error.
*/
public onsyserr(n, f)
int n;
INTFUNC *f;
{
if (errinfo == nil(ERRINFO *)) {
initErrInfo();
}
errinfo[n].func = f;
}
/*
* Print the message associated with the given signal.
* Like a "perror" for signals.
*/
public int sys_nsig = NSIG;
public psignal(s, n)
String s;
integer n;
{
String msg;
integer len;
extern String sys_siglist[];
if (n >= 0 and n < sys_nsig) {
msg = sys_siglist[n];
} else {
msg = "Unknown signal";
}
len = strlen(s);
if (len > 0) {
write(2, s, len);
write(2, ": ", 2);
}
write(2, msg, strlen(msg));
write(2, "\n", 1);
}
/*
* Standard error handling routines.
*/
private short nerrs;
private short nwarnings;
/*
* Main driver of error message reporting.
*/
/* VARARGS2 */
private errmsg(errname, shouldquit, s, a, b, c, d, e, f, g, h, i, j, k, l, m)
String errname;
boolean shouldquit;
String s;
{
fflush(stdout);
if (shouldquit and cmdname != nil(String)) {
fprintf(stderr, "%s: ", cmdname);
}
if (errfilename != nil(Filename)) {
fprintf(stderr, "%s: ", errfilename);
}
if (errlineno > 0) {
fprintf(stderr, "%d: ", errlineno);
}
if (errname != nil(String)) {
fprintf(stderr, "%s: ", errname);
}
fprintf(stderr, s, a, b, c, d, e, f, g, h, i, j, k, l, m);
putc('\n', stderr);
if (shouldquit) {
quit(1);
}
}
/*
* For when printf isn't sufficient for printing the error message ...
*/
public beginerrmsg()
{
fflush(stdout);
if (errfilename != nil(String)) {
fprintf(stderr, "%s: ", errfilename);
}
if (errlineno > 0) {
fprintf(stderr, "%d: ", errlineno);
}
}
public enderrmsg()
{
putc('\n', stderr);
erecover();
}
/*
* The messages are listed in increasing order of seriousness.
*
* First are warnings.
*/
/* VARARGS1 */
public warning(s, a, b, c, d, e, f, g, h, i, j, k, l, m)
String s;
{
nwarnings++;
errmsg("warning", FALSE, s, a, b, c, d, e, f, g, h, i, j, k, l, m);
}
/*
* Errors are a little worse, they mean something is wrong,
* but not so bad that processing can't continue.
*
* The routine "erecover" is called to recover from the error,
* a default routine is provided that does nothing.
*/
/* VARARGS1 */
public error(s, a, b, c, d, e, f, g, h, i, j, k, l, m)
String s;
{
extern erecover();
nerrs++;
errmsg(nil(String), FALSE, s, a, b, c, d, e, f, g, h, i, j, k, l, m);
erecover();
}
/*
* Non-recoverable user error.
*/
/* VARARGS1 */
public fatal(s, a, b, c, d, e, f, g, h, i, j, k, l, m)
String s;
{
errmsg("fatal error", TRUE, s, a, b, c, d, e, f, g, h, i, j, k, l, m);
}
/*
* Panics indicate an internal program error.
*/
/* VARARGS1 */
public panic(s, a, b, c, d, e, f, g, h, i, j, k, l, m)
String s;
{
errmsg("internal error", TRUE, s, a, b, c, d, e, f, g, h, i, j, k, l, m);
}
short numerrors()
{
short r;
r = nerrs;
nerrs = 0;
return r;
}
short numwarnings()
{
short r;
r = nwarnings;
nwarnings = 0;
return r;
}
/*
* Recover from an error.
*
* This is the default routine which we aren't using since we have our own.
*
public erecover()
{
}
*
*/
/*
* Default way to quit from a program is just to exit.
*
public quit(r)
int r;
{
exit(r);
}
*
*/
/*
* Compare n-byte areas pointed to by s1 and s2
* if n is 0 then compare up until one has a null byte.
*/
public int cmp(s1, s2, n)
register char *s1, *s2;
register unsigned int n;
{
if (s1 == nil(char *) || s2 == nil(char *)) {
panic("cmp: nil pointer");
}
if (n == 0) {
while (*s1 == *s2++) {
if (*s1++ == '\0') {
return(0);
}
}
return(*s1 - *(s2-1));
} else {
for (; n != 0; n--) {
if (*s1++ != *s2++) {
return(*(s1-1) - *(s2-1));
}
}
return(0);
}
}
/*
* Move n bytes from src to dest.
* If n is 0 move until a null is found.
*/
public mov(src, dest, n)
register char *src, *dest;
register unsigned int n;
{
if (src == nil(char *))
panic("mov: nil source");
if (dest == nil(char *))
panic("mov: nil destination");
if (n != 0) {
for (; n != 0; n--) {
*dest++ = *src++;
}
} else {
while ((*dest++ = *src++) != '\0');
}
}