NetBSD/usr.bin/crunch/crunchgen/crunchgen.c

913 lines
21 KiB
C

/* $NetBSD: crunchgen.c,v 1.16 2000/06/11 14:31:11 mycroft Exp $ */
/*
* Copyright (c) 1994 University of Maryland
* All Rights Reserved.
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of U.M. not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. U.M. makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
* U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
* BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: James da Silva, Systems Design and Analysis Group
* Computer Science Department
* University of Maryland at College Park
*/
/*
* ========================================================================
* crunchgen.c
*
* Generates a Makefile and main C file for a crunched executable,
* from specs given in a .conf file.
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: crunchgen.c,v 1.16 2000/06/11 14:31:11 mycroft Exp $");
#endif
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/utsname.h>
#define CRUNCH_VERSION "0.2"
#define MAXLINELEN 16384
#define MAXFIELDS 2048
/* internal representation of conf file: */
/* simple lists of strings suffice for most parms */
typedef struct strlst {
struct strlst *next;
char *str;
} strlst_t;
/* progs have structure, each field can be set with "special" or calculated */
typedef struct prog {
struct prog *next;
char *name, *ident;
char *srcdir, *objdir;
strlst_t *objs, *objpaths;
strlst_t *links;
int goterror;
} prog_t;
/* global state */
strlst_t *srcdirs = NULL;
strlst_t *libs = NULL;
prog_t *progs = NULL;
char line[MAXLINELEN];
char confname[MAXPATHLEN], infilename[MAXPATHLEN];
char outmkname[MAXPATHLEN], outcfname[MAXPATHLEN], execfname[MAXPATHLEN];
char tempfname[MAXPATHLEN], cachename[MAXPATHLEN], curfilename[MAXPATHLEN];
char topdir[MAXPATHLEN];
char libdir[MAXPATHLEN] = "/usr/lib";
int linenum = -1;
int goterror = 0;
char *pname = "crunchgen";
int verbose, readcache; /* options */
int reading_cache;
char *machine;
/* general library routines */
void status(char *str);
void out_of_memory(void);
void add_string(strlst_t **listp, char *str);
int is_dir(char *pathname);
int is_nonempty_file(char *pathname);
/* helper routines for main() */
void usage(void);
void parse_conf_file(void);
void gen_outputs(void);
int main(int argc, char **argv)
{
char *p;
int optc;
if ((machine = getenv("MACHINE")) == NULL) {
struct utsname utsname;
if (uname(&utsname) == -1) {
perror("uname");
exit(1);
}
machine = utsname.machine;
}
verbose = 1;
readcache = 1;
*outmkname = *outcfname = *execfname = '\0';
if(argc > 0) pname = argv[0];
while((optc = getopt(argc, argv, "m:c:e:fqD:L:")) != -1) {
switch(optc) {
case 'f': readcache = 0; break;
case 'q': verbose = 0; break;
case 'm': strcpy(outmkname, optarg); break;
case 'c': strcpy(outcfname, optarg); break;
case 'e': strcpy(execfname, optarg); break;
case 'D': strcpy(topdir, optarg); break;
case 'L': strcpy(libdir, optarg); break;
case '?':
default: usage();
}
}
argc -= optind;
argv += optind;
if(argc != 1) usage();
/*
* generate filenames
*/
strcpy(infilename, argv[0]);
/* confname = `basename infilename .conf` */
if((p=strrchr(infilename, '/')) != NULL) strcpy(confname, p+1);
else strcpy(confname, infilename);
if((p=strrchr(confname, '.')) != NULL && !strcmp(p, ".conf")) *p = '\0';
if (!*outmkname)
(void)snprintf(outmkname, sizeof(outmkname), "%s.mk", confname);
if (!*outcfname)
(void)snprintf(outcfname, sizeof(outcfname), "%s.c", confname);
if (!*execfname)
(void)snprintf(execfname, sizeof(execfname), "%s", confname);
(void)snprintf(cachename, sizeof(cachename), "%s.cache", confname);
(void)snprintf(tempfname, sizeof(tempfname), "/tmp/%sXXXXXX", confname);
parse_conf_file();
gen_outputs();
exit(goterror);
}
void usage(void)
{
fprintf(stderr,
"%s [-fq] [-m <makefile>] [-c <c file>] [-e <exec file>] <conffile>\n",
pname);
exit(1);
}
/*
* ========================================================================
* parse_conf_file subsystem
*
*/
/* helper routines for parse_conf_file */
void parse_one_file(char *filename);
void parse_line(char *line, int *fc, char **fv, int nf);
void add_srcdirs(int argc, char **argv);
void add_progs(int argc, char **argv);
void add_link(int argc, char **argv);
void add_libs(int argc, char **argv);
void add_special(int argc, char **argv);
prog_t *find_prog(char *str);
void add_prog(char *progname);
void parse_conf_file(void)
{
if(!is_nonempty_file(infilename)) {
fprintf(stderr, "%s: fatal: input file \"%s\" not found.\n",
pname, infilename);
exit(1);
}
parse_one_file(infilename);
if(readcache && is_nonempty_file(cachename)) {
reading_cache = 1;
parse_one_file(cachename);
}
}
void parse_one_file(char *filename)
{
char *fieldv[MAXFIELDS];
int fieldc;
void (*f)(int c, char **v);
FILE *cf;
(void)snprintf(line, sizeof(line), "reading %s", filename);
status(line);
strcpy(curfilename, filename);
if((cf = fopen(curfilename, "r")) == NULL) {
perror(curfilename);
goterror = 1;
return;
}
linenum = 0;
while(fgets(line, MAXLINELEN, cf) != NULL) {
linenum++;
parse_line(line, &fieldc, fieldv, MAXFIELDS);
if(fieldc < 1) continue;
if(!strcmp(fieldv[0], "srcdirs")) f = add_srcdirs;
else if(!strcmp(fieldv[0], "progs")) f = add_progs;
else if(!strcmp(fieldv[0], "ln")) f = add_link;
else if(!strcmp(fieldv[0], "libs")) f = add_libs;
else if(!strcmp(fieldv[0], "special")) f = add_special;
else {
fprintf(stderr, "%s:%d: skipping unknown command `%s'.\n",
curfilename, linenum, fieldv[0]);
goterror = 1;
continue;
}
if(fieldc < 2) {
fprintf(stderr,
"%s:%d: %s command needs at least 1 argument, skipping.\n",
curfilename, linenum, fieldv[0]);
goterror = 1;
continue;
}
f(fieldc, fieldv);
}
if(ferror(cf)) {
perror(curfilename);
goterror = 1;
}
fclose(cf);
}
void parse_line(char *line, int *fc, char **fv, int nf)
{
char *p;
p = line;
*fc = 0;
while(1) {
while(isspace(*p)) p++;
if(*p == '\0' || *p == '#') break;
if(*fc < nf) fv[(*fc)++] = p;
while(*p && !isspace(*p) && *p != '#') p++;
if(*p == '\0' || *p == '#') break;
*p++ = '\0';
}
if(*p) *p = '\0'; /* needed for '#' case */
}
void add_srcdirs(int argc, char **argv)
{
int i;
char tmppath[MAXPATHLEN];
for(i=1;i<argc;i++) {
if (argv[i][0] == '/' || topdir[0] == '\0')
strcpy(tmppath, argv[i]);
else {
strcpy(tmppath, topdir);
strcat(tmppath, "/");
strcat(tmppath, argv[i]);
}
if(is_dir(tmppath))
add_string(&srcdirs, tmppath);
else {
fprintf(stderr, "%s:%d: `%s' is not a directory, skipping it.\n",
curfilename, linenum, tmppath);
goterror = 1;
}
}
}
void add_progs(int argc, char **argv)
{
int i;
for(i=1;i<argc;i++)
add_prog(argv[i]);
}
void add_prog(char *progname)
{
prog_t *p1, *p2;
/* add to end, but be smart about dups */
for(p1 = NULL, p2 = progs; p2 != NULL; p1 = p2, p2 = p2->next)
if(!strcmp(p2->name, progname)) return;
p2 = malloc(sizeof(prog_t));
if(p2) p2->name = strdup(progname);
if(!p2 || !p2->name)
out_of_memory();
p2->next = NULL;
if(p1 == NULL) progs = p2;
else p1->next = p2;
p2->ident = p2->srcdir = p2->objdir = NULL;
p2->objs = p2->objpaths = p2->links = NULL;
p2->goterror = 0;
}
void add_link(int argc, char **argv)
{
int i;
prog_t *p = find_prog(argv[1]);
if(p == NULL) {
fprintf(stderr,
"%s:%d: no prog %s previously declared, skipping link.\n",
curfilename, linenum, argv[1]);
goterror = 1;
return;
}
for(i=2;i<argc;i++)
add_string(&p->links, argv[i]);
}
void add_libs(int argc, char **argv)
{
int i;
for(i=1;i<argc;i++)
add_string(&libs, argv[i]);
}
void add_special(int argc, char **argv)
{
int i;
prog_t *p = find_prog(argv[1]);
if(p == NULL) {
if(reading_cache) return;
fprintf(stderr,
"%s:%d: no prog %s previously declared, skipping special.\n",
curfilename, linenum, argv[1]);
goterror = 1;
return;
}
if(!strcmp(argv[2], "ident")) {
if(argc != 4) goto argcount;
if((p->ident = strdup(argv[3])) == NULL)
out_of_memory();
}
else if(!strcmp(argv[2], "srcdir")) {
if(argc != 4) goto argcount;
if (argv[3][0] == '/' || topdir[0] == '\0') {
if((p->srcdir = strdup(argv[3])) == NULL)
out_of_memory();
} else {
char tmppath[MAXPATHLEN];
strcpy(tmppath, topdir);
strcat(tmppath, "/");
strcat(tmppath, argv[3]);
if((p->srcdir = strdup(tmppath)) == NULL)
out_of_memory();
}
}
else if(!strcmp(argv[2], "objdir")) {
if(argc != 4) goto argcount;
if((p->objdir = strdup(argv[3])) == NULL)
out_of_memory();
}
else if(!strcmp(argv[2], "objs")) {
p->objs = NULL;
for(i=3;i<argc;i++)
add_string(&p->objs, argv[i]);
}
else if(!strcmp(argv[2], "objpaths")) {
p->objpaths = NULL;
for(i=3;i<argc;i++)
add_string(&p->objpaths, argv[i]);
}
else {
fprintf(stderr, "%s:%d: bad parameter name `%s', skipping line.\n",
curfilename, linenum, argv[2]);
goterror = 1;
}
return;
argcount:
fprintf(stderr,
"%s:%d: too %s arguments, expected \"special %s %s <string>\".\n",
curfilename, linenum, argc < 4? "few" : "many", argv[1], argv[2]);
goterror = 1;
}
prog_t *find_prog(char *str)
{
prog_t *p;
for(p = progs; p != NULL; p = p->next)
if(!strcmp(p->name, str)) return p;
return NULL;
}
/*
* ========================================================================
* gen_outputs subsystem
*
*/
/* helper subroutines */
void remove_error_progs(void);
void fillin_program(prog_t *p);
void gen_specials_cache(void);
void gen_output_makefile(void);
void gen_output_cfile(void);
void fillin_program_objs(prog_t *p, char *path);
void top_makefile_rules(FILE *outmk);
void prog_makefile_rules(FILE *outmk, prog_t *p);
void output_strlst(FILE *outf, strlst_t *lst);
char *genident(char *str);
char *dir_search(char *progname);
void gen_outputs(void)
{
prog_t *p;
for(p = progs; p != NULL; p = p->next)
fillin_program(p);
remove_error_progs();
gen_specials_cache();
gen_output_cfile();
gen_output_makefile();
status("");
fprintf(stderr,
"Run \"make -f %s objs exe\" to build crunched binary.\n",
outmkname);
}
void fillin_program(prog_t *p)
{
char path[MAXPATHLEN];
char *srcparent;
strlst_t *s;
(void)snprintf(line, sizeof(line), "filling in parms for %s", p->name);
status(line);
if(!p->ident)
p->ident = genident(p->name);
if(!p->srcdir) {
srcparent = dir_search(p->name);
if(srcparent) {
(void)snprintf(path, sizeof(path), "%s/%s", srcparent, p->name);
if(is_dir(path))
p->srcdir = strdup(path);
}
}
if(!p->objdir && p->srcdir) {
(void)snprintf(path, sizeof(path), "%s/obj.%s", p->srcdir, machine);
if(is_dir(path))
p->objdir = strdup(path);
else {
(void)snprintf(path, sizeof(path), "%s/obj", p->srcdir);
if(is_dir(path))
p->objdir = strdup(path);
else
p->objdir = p->srcdir;
}
}
if(p->srcdir)
(void)snprintf(path, sizeof(path), "%s/Makefile", p->srcdir);
if(!p->objs && p->srcdir && is_nonempty_file(path))
fillin_program_objs(p, p->srcdir);
if(!p->objpaths && p->objdir && p->objs)
for(s = p->objs; s != NULL; s = s->next) {
(void)snprintf(line, sizeof(line), "%s/%s", p->objdir, s->str);
add_string(&p->objpaths, line);
}
if(!p->srcdir && verbose)
fprintf(stderr, "%s: %s: warning: could not find source directory.\n",
infilename, p->name);
if(!p->objs && verbose)
fprintf(stderr, "%s: %s: warning: could not find any .o files.\n",
infilename, p->name);
if(!p->objpaths) {
fprintf(stderr,
"%s: %s: error: no objpaths specified or calculated.\n",
infilename, p->name);
p->goterror = goterror = 1;
}
}
void fillin_program_objs(prog_t *p, char *dirpath)
{
char *obj, *cp;
int rc;
int fd;
FILE *f;
/* discover the objs from the srcdir Makefile */
if((fd = mkstemp(tempfname)) < 0) {
perror(tempfname);
exit(1);
}
if((f = fdopen(fd, "w")) == NULL) {
perror(tempfname);
goterror = 1;
return;
}
fprintf(f, ".include \"${.CURDIR}/Makefile\"\n");
fprintf(f, ".if defined(PROG)\n");
fprintf(f, "OBJS?= ${PROG}.o\n");
fprintf(f, ".endif\n");
fprintf(f, "crunchgen_objs:\n\t@echo 'OBJS= '${OBJS}\n");
fclose(f);
(void)snprintf(line, sizeof(line),
"cd %s && make -f %s crunchgen_objs 2>&1", dirpath, tempfname);
if((f = popen(line, "r+")) == NULL) {
perror("submake pipe");
goterror = 1;
return;
}
while(fgets(line, MAXLINELEN, f)) {
if(strncmp(line, "OBJS= ", 6)) {
if (strcmp(line,
"sh: warning: running as root with dot in PATH\n") == 0)
continue;
fprintf(stderr, "make error: %s", line);
goterror = 1;
continue;
}
cp = line + 6;
while(isspace(*cp)) cp++;
while(*cp) {
obj = cp;
while(*cp && !isspace(*cp)) cp++;
if(*cp) *cp++ = '\0';
add_string(&p->objs, obj);
while(isspace(*cp)) cp++;
}
}
if((rc=pclose(f)) != 0) {
fprintf(stderr, "make error: make returned %d\n", rc);
goterror = 1;
}
unlink(tempfname);
}
void remove_error_progs(void)
{
prog_t *p1, *p2;
p1 = NULL; p2 = progs;
while(p2 != NULL) {
if(!p2->goterror)
p1 = p2, p2 = p2->next;
else {
/* delete it from linked list */
fprintf(stderr, "%s: %s: ignoring program because of errors.\n",
infilename, p2->name);
if(p1) p1->next = p2->next;
else progs = p2->next;
p2 = p2->next;
}
}
}
void gen_specials_cache(void)
{
FILE *cachef;
prog_t *p;
(void)snprintf(line, sizeof(line), "generating %s", cachename);
status(line);
if((cachef = fopen(cachename, "w")) == NULL) {
perror(cachename);
goterror = 1;
return;
}
fprintf(cachef, "# %s - parm cache generated from %s by crunchgen %s\n\n",
cachename, infilename, CRUNCH_VERSION);
for(p = progs; p != NULL; p = p->next) {
fprintf(cachef, "\n");
if(p->srcdir)
fprintf(cachef, "special %s srcdir %s\n", p->name, p->srcdir);
if(p->objdir)
fprintf(cachef, "special %s objdir %s\n", p->name, p->objdir);
if(p->objs) {
fprintf(cachef, "special %s objs", p->name);
output_strlst(cachef, p->objs);
}
fprintf(cachef, "special %s objpaths", p->name);
output_strlst(cachef, p->objpaths);
}
fclose(cachef);
}
void gen_output_makefile(void)
{
prog_t *p;
FILE *outmk;
(void)snprintf(line, sizeof(line), "generating %s", outmkname);
status(line);
if((outmk = fopen(outmkname, "w")) == NULL) {
perror(outmkname);
goterror = 1;
return;
}
fprintf(outmk, "# %s - generated from %s by crunchgen %s\n\n",
outmkname, infilename, CRUNCH_VERSION);
top_makefile_rules(outmk);
for(p = progs; p != NULL; p = p->next)
prog_makefile_rules(outmk, p);
fprintf(outmk, "\n.include <bsd.sys.mk>\n");
fprintf(outmk, "\n# ========\n");
fclose(outmk);
}
void gen_output_cfile(void)
{
extern char *crunched_skel[];
char **cp;
FILE *outcf;
prog_t *p;
strlst_t *s;
(void)snprintf(line, sizeof(line), "generating %s", outcfname);
status(line);
if((outcf = fopen(outcfname, "w")) == NULL) {
perror(outcfname);
goterror = 1;
return;
}
fprintf(outcf,
"/* %s - generated from %s by crunchgen %s */\n",
outcfname, infilename, CRUNCH_VERSION);
fprintf(outcf, "#define EXECNAME \"%s\"\n", execfname);
for(cp = crunched_skel; *cp != NULL; cp++)
fprintf(outcf, "%s\n", *cp);
for(p = progs; p != NULL; p = p->next)
fprintf(outcf, "extern int _crunched_%s_stub();\n", p->ident);
fprintf(outcf, "\nstruct stub entry_points[] = {\n");
for(p = progs; p != NULL; p = p->next) {
fprintf(outcf, "\t{ \"%s\", _crunched_%s_stub },\n",
p->name, p->ident);
for(s = p->links; s != NULL; s = s->next)
fprintf(outcf, "\t{ \"%s\", _crunched_%s_stub },\n",
s->str, p->ident);
}
fprintf(outcf, "\t{ EXECNAME, crunched_main },\n");
fprintf(outcf, "\t{ NULL, NULL }\n};\n");
fclose(outcf);
}
char *genident(char *str)
{
char *n,*s,*d;
/*
* generates a Makefile/C identifier from a program name, mapping '-' to
* '_' and ignoring all other non-identifier characters. This leads to
* programs named "foo.bar" and "foobar" to map to the same identifier.
*/
if((n = strdup(str)) == NULL)
return NULL;
for(d = s = n; *s != '\0'; s++) {
if(*s == '-') *d++ = '_';
else if(*s == '_' || isalnum(*s)) *d++ = *s;
}
*d = '\0';
return n;
}
char *dir_search(char *progname)
{
char path[MAXPATHLEN];
strlst_t *dir;
for(dir=srcdirs; dir != NULL; dir=dir->next) {
(void)snprintf(path, sizeof(path), "%s/%s", dir->str, progname);
if(is_dir(path)) return dir->str;
}
return NULL;
}
void top_makefile_rules(FILE *outmk)
{
prog_t *p;
fprintf(outmk, "STRIP?=strip\n");
fprintf(outmk, "LIBS=");
fprintf(outmk, "-L%s ", libdir);
output_strlst(outmk, libs);
fprintf(outmk, "CRUNCHED_OBJS=");
for(p = progs; p != NULL; p = p->next)
fprintf(outmk, " %s.cro", p->name);
fprintf(outmk, "\n");
fprintf(outmk, "SUBMAKE_TARGETS=");
for(p = progs; p != NULL; p = p->next)
fprintf(outmk, " %s_make", p->ident);
fprintf(outmk, "\n\n");
fprintf(outmk, "%s: %s.o $(CRUNCHED_OBJS)\n",
execfname, execfname);
fprintf(outmk, "\t$(CC) -static -o %s %s.o $(CRUNCHED_OBJS) $(LIBS)\n",
execfname, execfname);
fprintf(outmk, "\t$(STRIP) %s\n", execfname);
fprintf(outmk, "all: objs exe\nobjs: $(SUBMAKE_TARGETS)\n");
fprintf(outmk, "exe: %s\n", execfname);
fprintf(outmk, "clean:\n\trm -f %s *.cro *.o *_stub.c\n",
execfname);
}
void prog_makefile_rules(FILE *outmk, prog_t *p)
{
fprintf(outmk, "\n# -------- %s\n\n", p->name);
if(p->srcdir && p->objs) {
fprintf(outmk, "%s_SRCDIR=%s\n", p->ident, p->srcdir);
fprintf(outmk, "%s_OBJS=", p->ident);
output_strlst(outmk, p->objs);
fprintf(outmk, "%s_make:\n", p->ident);
fprintf(outmk, "\t(cd $(%s_SRCDIR); make $(%s_OBJS))\n\n",
p->ident, p->ident);
}
else
fprintf(outmk, "%s_make:\n\t@echo \"** cannot make objs for %s\"\n\n",
p->ident, p->name);
fprintf(outmk, "%s_OBJPATHS=", p->ident);
output_strlst(outmk, p->objpaths);
fprintf(outmk, "%s_stub.c:\n", p->name);
fprintf(outmk, "\techo \""
"int _crunched_%s_stub(int argc, char **argv, char **envp)"
"{return main(argc,argv,envp);}\" >%s_stub.c\n",
p->ident, p->name);
fprintf(outmk, "%s.cro: %s_stub.o $(%s_OBJPATHS)\n",
p->name, p->name, p->ident);
fprintf(outmk, "\t${LD} -dc -r -o %s.cro %s_stub.o $(%s_OBJPATHS)\n",
p->name, p->name, p->ident);
fprintf(outmk, "\tcrunchide -k _crunched_%s_stub %s.cro\n",
p->ident, p->name);
}
void output_strlst(FILE *outf, strlst_t *lst)
{
for(; lst != NULL; lst = lst->next)
fprintf(outf, " %s", lst->str);
fprintf(outf, "\n");
}
/*
* ========================================================================
* general library routines
*
*/
void status(char *str)
{
static int lastlen = 0;
int len, spaces;
if(!verbose) return;
len = strlen(str);
spaces = lastlen - len;
if(spaces < 1) spaces = 1;
fprintf(stderr, " [%s]%*.*s\r", str, spaces, spaces, " ");
fflush(stderr);
lastlen = len;
}
void out_of_memory(void)
{
fprintf(stderr, "%s: %d: out of memory, stopping.\n", infilename, linenum);
exit(1);
}
void add_string(strlst_t **listp, char *str)
{
strlst_t *p1, *p2;
/* add to end, but be smart about dups */
for(p1 = NULL, p2 = *listp; p2 != NULL; p1 = p2, p2 = p2->next)
if(!strcmp(p2->str, str)) return;
p2 = malloc(sizeof(strlst_t));
if(p2) p2->str = strdup(str);
if(!p2 || !p2->str)
out_of_memory();
p2->next = NULL;
if(p1 == NULL) *listp = p2;
else p1->next = p2;
}
int is_dir(char *pathname)
{
struct stat buf;
if(stat(pathname, &buf) == -1)
return 0;
return S_ISDIR(buf.st_mode);
}
int is_nonempty_file(char *pathname)
{
struct stat buf;
if(stat(pathname, &buf) == -1)
return 0;
return S_ISREG(buf.st_mode) && buf.st_size > 0;
}