18980: new zsh/system module

1 files changed, 418 insertions, 0 deletions

diff --git a/Src/Modules/system.c b/Src/Modules/system.c
new file mode 100644
index 000000000..174bf133d
--- /dev/null
+++ b/Src/Modules/system.c
@@ -0,0 +1,418 @@
+/*
+ * sysread.c - interface to system read/write
+ *
+ * This file is part of zsh, the Z shell.
+ *
+ * Copyright (c) 1998-2003 Peter Stephenson
+ * All rights reserved.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and to distribute modified versions of this software for any
+ * purpose, provided that the above copyright notice and the following
+ * two paragraphs appear in all copies of this software.
+ *
+ * In no event shall Peter Stephenson or the Zsh Development
+ * Group be liable to any party for direct, indirect, special, incidental,
+ * or consequential damages arising out of the use of this software and
+ * its documentation, even if Peter Stephenson, and the Zsh
+ * Development Group have been advised of the possibility of such damage.
+ *
+ * Peter Stephenson and the Zsh Development Group specifically
+ * disclaim any warranties, including, but not limited to, the implied
+ * warranties of merchantability and fitness for a particular purpose.  The
+ * software provided hereunder is on an "as is" basis, and Peter Stephenson
+ * and the Zsh Development Group have no obligation to provide maintenance,
+ * support, updates, enhancements, or modifications.
+ *
+ */
+
+#include "system.mdh"
+#include "system.pro"
+
+#ifdef HAVE_POLL_H
+# include <poll.h>
+#endif
+#if defined(HAVE_POLL) && !defined(POLLIN)
+# undef HAVE_POLL
+#endif
+
+#define SYSREAD_BUFSIZE	8192
+
+/**/
+static int
+getposint(char *instr, char *nam)
+{
+    char *eptr;
+    int ret;
+
+    ret = (int)zstrtol(instr, &eptr, 10);
+    if (*eptr || ret < 0) {
+	zwarnnam(nam, "integer expected: %s", instr, 0);
+	return -1;
+    }
+
+    return ret;
+}
+
+
+/*
+ * Return values of bin_sysread:
+ *	0	Successfully read (and written if appropriate)
+ *	1	Error in parameters to command
+ *	2	Error on read, or polling read fd ) ERRNO set by
+ *      3	Error on write			  ) system
+ *	4	Timeout on read
+ *	5       Zero bytes read, end of file
+ */
+
+/**/
+static int
+bin_sysread(char *nam, char **args, Options ops, int func)
+{
+    int infd = 0, outfd = -1, bufsize = SYSREAD_BUFSIZE, count;
+    char *outvar = NULL, *countvar = NULL, *inbuf;
+
+    /* -i: input file descriptor if not stdin */
+    if (OPT_ISSET(ops, 'i')) {
+	infd = getposint(OPT_ARG(ops, 'i'), nam);
+	if (infd < 0)
+	    return 1;
+    }
+
+    /* -o: output file descriptor, else store in REPLY */
+    if (OPT_ISSET(ops, 'o')) {
+	if (*args) {
+	    zwarnnam(nam, "no argument allowed with -o", NULL, 0);
+	    return 1;
+	}
+	outfd = getposint(OPT_ARG(ops, 'o'), nam);
+	if (outfd < 0)
+	    return 1;
+    }
+
+    /* -s: buffer size if not default SYSREAD_BUFSIZE */
+    if (OPT_ISSET(ops, 's')) {
+	bufsize = getposint(OPT_ARG(ops, 's'), nam);
+	if (bufsize < 0)
+	    return 1;
+    }
+
+    /* -c: name of variable to store count of transferred bytes */
+    if (OPT_ISSET(ops, 'c')) {
+	countvar = OPT_ARG(ops, 'c');
+	if (!isident(countvar)) {
+	    zwarnnam(nam, "not an identifier: %s", countvar, 0);
+	    return 1;
+	}
+    }
+
+    if (*args) {
+	/*
+	 * Variable in which to store result if doing a plain read.
+	 * Default variable if not specified is REPLY.
+	 * If writing, only stuff we couldn't write is stored here,
+	 * no default in that case (we just discard it if no variable).
+	 */
+	outvar = *args;
+	if (!isident(outvar)) {
+	    zwarnnam(nam, "not an identifier: %s", outvar, 0);
+	    return 1;
+	}
+    }
+
+    inbuf = zhalloc(bufsize);
+
+#if defined(HAVE_POLL) || defined(HAVE_SELECT)
+    /* -t: timeout */
+    if (OPT_ISSET(ops, 't'))
+    {
+# ifdef HAVE_POLL
+	struct pollfd poll_fd;
+	mnumber to_mn;
+	int to_int, ret;
+
+	poll_fd.fd = infd;
+	poll_fd.events = POLLIN;
+
+	to_mn = matheval(OPT_ARG(ops, 't'));
+	if (errflag)
+	    return 1;
+	if (to_mn.type == MN_FLOAT)
+	    to_int = (int) (1000 * to_mn.u.d);
+	else
+	    to_int = 1000 * (int)to_mn.u.l;
+
+	while ((ret = poll(&poll_fd, 1, to_int)) < 0) {
+	    if (errno != EINTR || errflag || retflag || breaks || contflag)
+		break;
+	}
+	if (ret <= 0) {
+	    /* treat non-timeout error as error on read */
+	    return ret ? 2 : 4;
+	}
+# else
+	/* using select */
+	struct timeval select_tv;
+	fd_set fds;
+	mnumber to_mn;
+	int ret;
+
+	FD_ZERO(&fds);
+	FD_SET(infd, &fds);
+	to_mn = matheval(OPT_ARG(ops, 't'));
+	if (errflag)
+	    return 1;
+
+	if (to_mn.type == MN_FLOAT) {
+	    select_tv.tv_sec = (int) to_mn.u.d;
+	    select_tv.tv_usec =
+		(int) ((to_mn.u.d - select_tv.tv_sec) * 1e6);
+	} else {
+	    select_tv.tv_sec = (int) to_mn.u.l;
+	    select_tv.tv_usec = 0;
+	}
+
+	while ((ret = select(infd+1, (SELECT_ARG_2_T) &fds, 
+			     NULL, NULL,&select_tv)) < 1) {
+	    if (errno != EINTR || errflag || retflag || breaks || contflag)
+		break;
+	}
+	if (ret <= 0) {
+	    /* treat non-timeout error as error on read */
+	    return ret ? 2 : 4;
+	}
+# endif
+    }
+#endif
+
+    while ((count = read(infd, inbuf, bufsize)) < 0) {
+	if (errno != EINTR || errflag || retflag || breaks || contflag)
+	    break;
+    }
+    if (countvar)
+	setiparam(countvar, count);
+    if (count < 0)
+	return 2;
+
+    if (outfd >= 0) {
+	if (!count)
+	    return 5;
+	while (count > 0) {
+	    int ret;
+
+	    ret = write(outfd, inbuf, count);
+	    if (ret < 0) {
+		if (errno == EINTR && !errflag &&
+		    !retflag && !breaks && !contflag)
+		    continue;
+		if (outvar)
+		    setsparam(outvar, metafy(inbuf, count, META_DUP));
+		if (countvar)
+		    setiparam(countvar, count);
+		return 3;
+	    }
+	    inbuf += ret;
+	    count -= ret;
+	}
+	return 0;
+    }
+
+    if (!outvar)
+	    outvar = "REPLY";
+    /* do this even if we read zero bytes */
+    setsparam(outvar, metafy(inbuf, count, META_DUP));
+
+    return count ? 0 : 5;
+}
+
+
+/*
+ * Return values of bin_syswrite:
+ *	0	Successfully written
+ *	1	Error in parameters to command
+ *	2	Error on write, ERRNO set by system
+ */
+
+/**/
+static int
+bin_syswrite(char *nam, char **args, Options ops, int func)
+{
+    int outfd = 1, len, count, totcount;
+    char *countvar = NULL;
+
+    /* -o: output file descriptor if not stdout */
+    if (OPT_ISSET(ops, 'o')) {
+	outfd = getposint(OPT_ARG(ops, 'o'), nam);
+	if (outfd < 0)
+	    return 1;
+    }
+
+    /* -c: variable in which to store count of bytes written */
+    if (OPT_ISSET(ops, 'c')) {
+	countvar = OPT_ARG(ops, 'c');
+	if (!isident(countvar)) {
+	    zwarnnam(nam, "not an identifier: %s", countvar, 0);
+	    return 1;
+	}
+    }
+
+    totcount = 0;
+    unmetafy(*args, &len);
+    while (len) {
+	while ((count = write(outfd, *args, len)) < 0) {
+	    if (errno != EINTR || errflag || retflag || breaks || contflag)
+	    {
+		if (countvar)
+		    setiparam(countvar, totcount);
+		return 2;
+	    }
+	}
+	*args += count;
+	totcount += count;
+	len -= count;
+    }
+    if (countvar)
+	setiparam(countvar, totcount);
+
+    return 0;
+}
+
+
+/*
+ * Return values of bin_syserror:
+ *	0	Successfully processed error
+ *		(although if the number was invalid the string
+ *		may not be useful)
+ *	1	Error in parameters
+ *	2	Name of error not recognised.
+ */
+
+/**/
+static int
+bin_syserror(char *nam, char **args, Options ops, int func)
+{
+    int num = 0;
+    char *errvar = NULL, *msg, *pfx = "", *str;
+
+    /* variable in which to write error message */
+    if (OPT_ISSET(ops, 'e')) {
+	errvar = OPT_ARG(ops, 'e');
+	if (!isident(errvar)) {
+	    zwarnnam(nam, "not an identifier: %s", errvar, 0);
+	    return 1;
+	}
+    }
+    /* prefix for error message */
+    if (OPT_ISSET(ops, 'p'))
+	pfx = OPT_ARG(ops, 'p');
+
+    if (!*args)
+	num = errno;
+    else {
+	char *ptr = *args;
+	while (*ptr && idigit(*ptr))
+	    ptr++;
+	if (!*ptr && ptr > *args)
+	    num = atoi(*args);
+	else {
+	    const char **eptr;
+	    for (eptr = sys_errnames; *eptr; eptr++) {
+		if (!strcmp(*eptr, *args)) {
+		    num = (eptr - sys_errnames) + 1;
+		    break;
+		}
+	    }
+	    if (!*eptr)
+		return 2;
+	}
+    }
+
+    msg = strerror(num);
+    if (errvar) {
+	str = (char *)zalloc(strlen(msg) + strlen(pfx) + 1);
+	sprintf(str, "%s%s", pfx, msg);
+	setsparam(errvar, str);
+    } else {
+	fprintf(stderr, "%s%s\n", pfx, msg);
+    }
+
+    return 0;
+}
+
+
+/* Functions for the errnos special parameter. */
+
+/**/
+static char **
+errnosgetfn(Param pm)
+{
+    /* arrdup etc. should really take const pointers as arguments */
+    return arrdup((char **)sys_errnames);
+}
+
+
+static struct builtin bintab[] = {
+    BUILTIN("syserror", 0, bin_syserror, 0, 1, 0, "e:p:", NULL),
+    BUILTIN("sysread", 0, bin_sysread, 0, 1, 0, "c:i:o:s:t:", NULL),
+    BUILTIN("syswrite", 0, bin_syswrite, 1, 1, 0, "c:o:", NULL),
+};
+
+
+/* The load/unload routines required by the zsh library interface */
+
+/**/
+int
+setup_(Module m)
+{
+    return 0;
+}
+
+/**/
+static void
+tidyparam(Param pm)
+{
+    if (!pm)
+	return;
+    pm->flags &= ~PM_READONLY;
+    unsetparam_pm(pm, 0, 1);
+}
+
+
+/**/
+int
+boot_(Module m)
+{
+    Param pm_nos;
+
+    /* this takes care of an autoload on errnos */
+    unsetparam("errnos");
+    if (!(pm_nos = createparam("errnos", PM_ARRAY|PM_SPECIAL|PM_READONLY|
+			       PM_HIDE|PM_HIDEVAL|PM_REMOVABLE)))
+	return 1;
+    pm_nos->gets.afn = errnosgetfn;
+
+    if (!addbuiltins(m->nam, bintab, sizeof(bintab)/sizeof(*bintab))) {
+	tidyparam(pm_nos);
+	return 1;
+    }
+    return 0;
+}
+
+
+/**/
+int
+cleanup_(Module m)
+{
+    tidyparam((Param)paramtab->getnode(paramtab, "errnos"));
+
+    deletebuiltins(m->nam, bintab, sizeof(bintab)/sizeof(*bintab));
+    return 0;
+}
+
+/**/
+int
+finish_(Module m)
+{
+    return 0;
+}