util/subst.c - pub/scm/linux/kernel/git/djwong/e2fsprogs - Git at Google

 /*
  * subst.c --- substitution program
  *
  * Subst is used as a quickie program to do @ substitutions
  *
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #else
 #define HAVE_SYS_STAT_H
 #define HAVE_SYS_TIME_H
 #endif
 #include <stdio.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <ctype.h>
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
 #include <fcntl.h>
 #include <time.h>
 #include <utime.h>
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif

 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #else
 extern char *optarg;
 extern int optind;
 #endif


 struct subst_entry {
 	char *name;
 	char *value;
 	struct subst_entry *next;
 };

 static struct subst_entry *subst_table = 0;

 static int add_subst(char *name, char *value)
 {
 	struct subst_entry	*ent = 0;

 	ent = (struct subst_entry *) malloc(sizeof(struct subst_entry));
 	if (!ent)
 		goto fail;
 	ent->name = (char *) malloc(strlen(name)+1);
 	if (!ent->name)
 		goto fail;
 	ent->value = (char *) malloc(strlen(value)+1);
 	if (!ent->value)
 		goto fail;
 	strcpy(ent->name, name);
 	strcpy(ent->value, value);
 	ent->next = subst_table;
 	subst_table = ent;
 	return 0;
 fail:
 	if (ent) {
 		free(ent->name);
 		free(ent);
 	}
 	return ENOMEM;
 }

 static struct subst_entry *fetch_subst_entry(char *name)
 {
 	struct subst_entry *ent;

 	for (ent = subst_table; ent; ent = ent->next) {
 		if (strcmp(name, ent->name) == 0)
 			break;
 	}
 	return ent;
 }

 /*
  * Given the starting and ending position of the replacement name,
  * check to see if it is valid, and pull it out if it is.
  */
 static char *get_subst_symbol(const char *begin, size_t len, char prefix)
 {
 	static char replace_name[128];
 	char *cp, *start;

 	start = replace_name;
 	if (prefix)
 		*start++ = prefix;

 	if (len > sizeof(replace_name)-2)
 		return NULL;
 	memcpy(start, begin, len);
 	start[len] = 0;

 	/*
 	 * The substitution variable must all be in the of [0-9A-Za-z_].
 	 * If it isn't, this must be an invalid symbol name.
 	 */
 	for (cp = start; *cp; cp++) {
 		if (!(*cp >= 'a' && *cp <= 'z') &&
 		    !(*cp >= 'A' && *cp <= 'Z') &&
 		    !(*cp >= '0' && *cp <= '9') &&
 		    !(*cp == '_'))
 			return NULL;
 	}
 	return (replace_name);
 }

 static void replace_string(char *begin, char *end, char *newstr)
 {
 	int	replace_len, len;

 	replace_len = strlen(newstr);
 	len = end - begin;
 	if (replace_len == 0)
 		memmove(begin, end+1, strlen(end)+1);
 	else if (replace_len != len+1)
 		memmove(end+(replace_len-len-1), end,
 			strlen(end)+1);
 	memcpy(begin, newstr, replace_len);
 }

 static void substitute_line(char *line)
 {
 	char	*ptr, *name_ptr, *end_ptr;
 	struct subst_entry *ent;
 	char	*replace_name;
 	size_t	len;

 	/*
 	 * Expand all @FOO@ substitutions
 	 */
 	ptr = line;
 	while (ptr) {
 		name_ptr = strchr(ptr, '@');
 		if (!name_ptr)
 			break;	/* No more */
 		if (*(++name_ptr) == '@') {
 			/*
 			 * Handle tytso@@mit.edu --> tytso@mit.edu
 			 */
 			memmove(name_ptr-1, name_ptr, strlen(name_ptr)+1);
 			ptr = name_ptr+1;
 			continue;
 		}
 		end_ptr = strchr(name_ptr, '@');
 		if (!end_ptr)
 			break;
 		len = end_ptr - name_ptr;
 		replace_name = get_subst_symbol(name_ptr, len, 0);
 		if (!replace_name) {
 			ptr = name_ptr;
 			continue;
 		}
 		ent = fetch_subst_entry(replace_name);
 		if (!ent) {
 			fprintf(stderr, "Unfound expansion: '%s'\n",
 				replace_name);
 			ptr = end_ptr + 1;
 			continue;
 		}
 #if 0
 		fprintf(stderr, "Replace name = '%s' with '%s'\n",
 		       replace_name, ent->value);
 #endif
 		ptr = name_ptr-1;
 		replace_string(ptr, end_ptr, ent->value);
 		if ((ent->value[0] == '@') &&
 		    (strlen(replace_name) == strlen(ent->value)-2) &&
 		    !strncmp(replace_name, ent->value+1,
 			     strlen(ent->value)-2))
 			/* avoid an infinite loop */
 			ptr += strlen(ent->value);
 	}
 	/*
 	 * Now do a second pass to expand ${FOO}
 	 */
 	ptr = line;
 	while (ptr) {
 		name_ptr = strchr(ptr, '$');
 		if (!name_ptr)
 			break;	/* No more */
 		if (*(++name_ptr) != '{') {
 			ptr = name_ptr;
 			continue;
 		}
 		name_ptr++;
 		end_ptr = strchr(name_ptr, '}');
 		if (!end_ptr)
 			break;
 		len = end_ptr - name_ptr;
 		replace_name = get_subst_symbol(name_ptr, len, '$');
 		if (!replace_name) {
 			ptr = name_ptr;
 			continue;
 		}
 		ent = fetch_subst_entry(replace_name);
 		if (!ent) {
 			ptr = end_ptr + 1;
 			continue;
 		}
 #if 0
 		fprintf(stderr, "Replace name = '%s' with '%s'\n",
 		       replace_name, ent->value);
 #endif
 		ptr = name_ptr-2;
 		replace_string(ptr, end_ptr, ent->value);
 	}
 }

 static void parse_config_file(FILE *f)
 {
 	char	line[2048];
 	char	*cp, *ptr;

 	while (!feof(f)) {
 		memset(line, 0, sizeof(line));
 		if (fgets(line, sizeof(line), f) == NULL)
 			break;
 		/*
 		 * Strip newlines and comments.
 		 */
 		cp = strchr(line, '\n');
 		if (cp)
 			*cp = 0;
 		cp = strchr(line, '#');
 		if (cp)
 			*cp = 0;
 		/*
 		 * Skip trailing and leading whitespace
 		 */
 		for (cp = line + strlen(line) - 1; cp >= line; cp--) {
 			if (*cp == ' ' || *cp == '\t')
 				*cp = 0;
 			else
 				break;
 		}
 		cp = line;
 		while (*cp && isspace(*cp))
 			cp++;
 		ptr = cp;
 		/*
 		 * Skip empty lines
 		 */
 		if (*ptr == 0)
 			continue;
 		/*
 		 * Ignore future extensions
 		 */
 		if (*ptr == '@')
 			continue;
 		/*
 		 * Parse substitutions
 		 */
 		for (cp = ptr; *cp; cp++)
 			if (isspace(*cp))
 				break;
 		*cp = 0;
 		for (cp++; *cp; cp++)
 			if (!isspace(*cp))
 				break;
 #if 0
 		printf("Substitute: '%s' for '%s'\n", ptr, cp ? cp : "<NULL>");
 #endif
 		add_subst(ptr, cp);
 	}
 }

 /*
  * Return 0 if the files are different, 1 if the files are the same.
  */
 static int compare_file(FILE *old_f, FILE *new_f)
 {
 	char	oldbuf[2048], newbuf[2048], *oldcp, *newcp;
 	int	retval;

 	while (1) {
 		oldcp = fgets(oldbuf, sizeof(oldbuf), old_f);
 		newcp = fgets(newbuf, sizeof(newbuf), new_f);
 		if (!oldcp && !newcp) {
 			retval = 1;
 			break;
 		}
 		if (!oldcp || !newcp || strcmp(oldbuf, newbuf)) {
 			retval = 0;
 			break;
 		}
 	}
 	return retval;
 }

 void set_utimes(const char *filename, int fd, const struct timeval times[2])
 {
 #ifdef HAVE_FUTIMES
 	if (futimes(fd, times) < 0)
 		perror("futimes");
 #elif HAVE_UTIMES
 	if (utimes(filename, times) < 0)
 		perror("utimes");
 #else
 	struct utimbuf ut;

 	ut.actime = times[0].tv_sec;
 	ut.modtime = times[1].tv_sec;
 	if (utime(filename, &ut) < 0)
 		perror("utime");
 #endif
 }


 int main(int argc, char **argv)
 {
 	char	line[2048];
 	int	c;
 	int	fd, ofd = -1;
 	FILE	*in, *out, *old = NULL;
 	char	*outfn = NULL, *newfn = NULL;
 	int	verbose = 0;
 	int	adjust_timestamp = 0;
 	int	got_atime = 0;
 	struct stat stbuf;
 	struct timeval tv[2];

 	while ((c = getopt (argc, argv, "f:tv")) != EOF) {
 		switch (c) {
 		case 'f':
 			in = fopen(optarg, "r");
 			if (!in) {
 				perror(optarg);
 				exit(1);
 			}
 			parse_config_file(in);
 			fclose(in);
 			break;
 		case 't':
 			adjust_timestamp++;
 			break;
 		case 'v':
 			verbose++;
 			break;
 		default:
 			fprintf(stderr, "%s: [-f config-file] [file]\n",
 				argv[0]);
 			break;
 		}
 	}
 	if (optind < argc) {
 		in = fopen(argv[optind], "r");
 		if (!in) {
 			perror(argv[optind]);
 			exit(1);
 		}
 		optind++;
 	} else
 		in = stdin;

 	if (optind < argc) {
 		outfn = argv[optind];
 		newfn = (char *) malloc(strlen(outfn)+20);
 		if (!newfn) {
 			fprintf(stderr, "Memory error!  Exiting.\n");
 			exit(1);
 		}
 		strcpy(newfn, outfn);
 		strcat(newfn, ".new");
 		ofd = open(newfn, O_CREAT|O_TRUNC|O_RDWR, 0644);
 		if (ofd < 0) {
 			perror(newfn);
 			exit(1);
 		}
 		out = fdopen(ofd, "w+");
 		if (!out) {
 			perror("fdopen");
 			exit(1);
 		}

 		fd = open(outfn, O_RDONLY);
 		if (fd > 0) {
 			/* save the original atime, if possible */
 			if (fstat(fd, &stbuf) == 0) {
 #if HAVE_STRUCT_STAT_ST_ATIM
 				tv[0].tv_sec = stbuf.st_atim.tv_sec;
 				tv[0].tv_usec = stbuf.st_atim.tv_nsec / 1000;
 #else
 				tv[0].tv_sec = stbuf.st_atime;
 				tv[0].tv_usec = 0;
 #endif
 				got_atime = 1;
 			}
 			old = fdopen(fd, "r");
 			if (!old)
 				close(fd);
 		}
 	} else {
 		out = stdout;
 		outfn = 0;
 	}

 	while (!feof(in)) {
 		if (fgets(line, sizeof(line), in) == NULL)
 			break;
 		substitute_line(line);
 		fputs(line, out);
 	}
 	fclose(in);
 	if (outfn) {
 		fflush(out);
 		rewind(out);
 		if (old && compare_file(old, out)) {
 			if (verbose)
 				printf("No change, keeping %s.\n", outfn);
 			if (adjust_timestamp) {
 				if (verbose)
 					printf("Updating modtime for %s\n", outfn);
 				if (gettimeofday(&tv[1], NULL) < 0) {
 					perror("gettimeofday");
 					exit(1);
 				}
 				if (got_atime == 0)
 					tv[0] = tv[1];
 				else if (verbose)
 					printf("Using original atime\n");
 				set_utimes(outfn, fileno(old), tv);
 			}
 			if (ofd >= 0)
 				(void) fchmod(ofd, 0444);
 			fclose(out);
 			if (unlink(newfn) < 0)
 				perror("unlink");
 		} else {
 			if (verbose)
 				printf("Creating or replacing %s.\n", outfn);
 			if (ofd >= 0)
 				(void) fchmod(ofd, 0444);
 			fclose(out);
 			if (old)
 				fclose(old);
 			old = NULL;
 			if (rename(newfn, outfn) < 0) {
 				perror("rename");
 				exit(1);
 			}
 		}
 	}
 	if (old)
 		fclose(old);
 	if (newfn)
 		free(newfn);
 	return (0);
 }
	/*
	* subst.c --- substitution program
	*
	* Subst is used as a quickie program to do @ substitutions
	*
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#else
	#define HAVE_SYS_STAT_H
	#define HAVE_SYS_TIME_H
	#endif
	#include <stdio.h>
	#include <errno.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <string.h>
	#include <ctype.h>
	#ifdef HAVE_SYS_TIME_H
	#include <sys/time.h>
	#endif
	#ifdef HAVE_SYS_TYPES_H
	#include <sys/types.h>
	#endif
	#ifdef HAVE_SYS_STAT_H
	#include <sys/stat.h>
	#endif
	#include <fcntl.h>
	#include <time.h>
	#include <utime.h>
	#ifdef HAVE_SYS_TIME_H
	#include <sys/time.h>
	#endif

	#ifdef HAVE_GETOPT_H
	#include <getopt.h>
	#else
	extern char *optarg;
	extern int optind;
	#endif


	struct subst_entry {
	char *name;
	char *value;
	struct subst_entry *next;
	};

	static struct subst_entry *subst_table = 0;

	static int add_subst(char name, char value)
	{
	struct subst_entry *ent = 0;

	ent = (struct subst_entry *) malloc(sizeof(struct subst_entry));
	if (!ent)
	goto fail;
	ent->name = (char *) malloc(strlen(name)+1);
	if (!ent->name)
	goto fail;
	ent->value = (char *) malloc(strlen(value)+1);
	if (!ent->value)
	goto fail;
	strcpy(ent->name, name);
	strcpy(ent->value, value);
	ent->next = subst_table;
	subst_table = ent;
	return 0;
	fail:
	if (ent) {
	free(ent->name);
	free(ent);
	}
	return ENOMEM;
	}

	static struct subst_entry fetch_subst_entry(char name)
	{
	struct subst_entry *ent;

	for (ent = subst_table; ent; ent = ent->next) {
	if (strcmp(name, ent->name) == 0)
	break;
	}
	return ent;
	}

	/*
	* Given the starting and ending position of the replacement name,
	* check to see if it is valid, and pull it out if it is.
	*/
	static char get_subst_symbol(const char begin, size_t len, char prefix)
	{
	static char replace_name[128];
	char cp, start;

	start = replace_name;
	if (prefix)
	*start++ = prefix;

	if (len > sizeof(replace_name)-2)
	return NULL;
	memcpy(start, begin, len);
	start[len] = 0;

	/*
	* The substitution variable must all be in the of [0-9A-Za-z_].
	* If it isn't, this must be an invalid symbol name.
	*/
	for (cp = start; *cp; cp++) {
	if (!(cp >= 'a' && cp <= 'z') &&
	!(cp >= 'A' && cp <= 'Z') &&
	!(cp >= '0' && cp <= '9') &&
	!(*cp == '_'))
	return NULL;
	}
	return (replace_name);
	}

	static void replace_string(char begin, char end, char *newstr)
	{
	int replace_len, len;

	replace_len = strlen(newstr);
	len = end - begin;
	if (replace_len == 0)
	memmove(begin, end+1, strlen(end)+1);
	else if (replace_len != len+1)
	memmove(end+(replace_len-len-1), end,
	strlen(end)+1);
	memcpy(begin, newstr, replace_len);
	}

	static void substitute_line(char *line)
	{
	char ptr, name_ptr, *end_ptr;
	struct subst_entry *ent;
	char *replace_name;
	size_t len;

	/*
	* Expand all @FOO@ substitutions
	*/
	ptr = line;
	while (ptr) {
	name_ptr = strchr(ptr, '@');
	if (!name_ptr)
	break; /* No more */
	if (*(++name_ptr) == '@') {
	/*
	* Handle tytso@@mit.edu --> tytso@mit.edu
	*/
	memmove(name_ptr-1, name_ptr, strlen(name_ptr)+1);
	ptr = name_ptr+1;
	continue;
	}
	end_ptr = strchr(name_ptr, '@');
	if (!end_ptr)
	break;
	len = end_ptr - name_ptr;
	replace_name = get_subst_symbol(name_ptr, len, 0);
	if (!replace_name) {
	ptr = name_ptr;
	continue;
	}
	ent = fetch_subst_entry(replace_name);
	if (!ent) {
	fprintf(stderr, "Unfound expansion: '%s'\n",
	replace_name);
	ptr = end_ptr + 1;
	continue;
	}
	#if 0
	fprintf(stderr, "Replace name = '%s' with '%s'\n",
	replace_name, ent->value);
	#endif
	ptr = name_ptr-1;
	replace_string(ptr, end_ptr, ent->value);
	if ((ent->value[0] == '@') &&
	(strlen(replace_name) == strlen(ent->value)-2) &&
	!strncmp(replace_name, ent->value+1,
	strlen(ent->value)-2))
	/* avoid an infinite loop */
	ptr += strlen(ent->value);
	}
	/*
	* Now do a second pass to expand ${FOO}
	*/
	ptr = line;
	while (ptr) {
	name_ptr = strchr(ptr, '$');
	if (!name_ptr)
	break; /* No more */
	if (*(++name_ptr) != '{') {
	ptr = name_ptr;
	continue;
	}
	name_ptr++;
	end_ptr = strchr(name_ptr, '}');
	if (!end_ptr)
	break;
	len = end_ptr - name_ptr;
	replace_name = get_subst_symbol(name_ptr, len, '$');
	if (!replace_name) {
	ptr = name_ptr;
	continue;
	}
	ent = fetch_subst_entry(replace_name);
	if (!ent) {
	ptr = end_ptr + 1;
	continue;
	}
	#if 0
	fprintf(stderr, "Replace name = '%s' with '%s'\n",
	replace_name, ent->value);
	#endif
	ptr = name_ptr-2;
	replace_string(ptr, end_ptr, ent->value);
	}
	}

	static void parse_config_file(FILE *f)
	{
	char line[2048];
	char cp, ptr;

	while (!feof(f)) {
	memset(line, 0, sizeof(line));
	if (fgets(line, sizeof(line), f) == NULL)
	break;
	/*
	* Strip newlines and comments.
	*/
	cp = strchr(line, '\n');
	if (cp)
	*cp = 0;
	cp = strchr(line, '#');
	if (cp)
	*cp = 0;
	/*
	* Skip trailing and leading whitespace
	*/
	for (cp = line + strlen(line) - 1; cp >= line; cp--) {
	if (cp == ' ' \|\| cp == '\t')
	*cp = 0;
	else
	break;
	}
	cp = line;
	while (cp && isspace(cp))
	cp++;
	ptr = cp;
	/*
	* Skip empty lines
	*/
	if (*ptr == 0)
	continue;
	/*
	* Ignore future extensions
	*/
	if (*ptr == '@')
	continue;
	/*
	* Parse substitutions
	*/
	for (cp = ptr; *cp; cp++)
	if (isspace(*cp))
	break;
	*cp = 0;
	for (cp++; *cp; cp++)
	if (!isspace(*cp))
	break;
	#if 0
	printf("Substitute: '%s' for '%s'\n", ptr, cp ? cp : "<NULL>");
	#endif
	add_subst(ptr, cp);
	}
	}

	/*
	* Return 0 if the files are different, 1 if the files are the same.
	*/
	static int compare_file(FILE old_f, FILE new_f)
	{
	char oldbuf[2048], newbuf[2048], oldcp, newcp;
	int retval;

	while (1) {
	oldcp = fgets(oldbuf, sizeof(oldbuf), old_f);
	newcp = fgets(newbuf, sizeof(newbuf), new_f);
	if (!oldcp && !newcp) {
	retval = 1;
	break;
	}
	if (!oldcp \|\| !newcp \|\| strcmp(oldbuf, newbuf)) {
	retval = 0;
	break;
	}
	}
	return retval;
	}

	void set_utimes(const char *filename, int fd, const struct timeval times[2])
	{
	#ifdef HAVE_FUTIMES
	if (futimes(fd, times) < 0)
	perror("futimes");
	#elif HAVE_UTIMES
	if (utimes(filename, times) < 0)
	perror("utimes");
	#else
	struct utimbuf ut;

	ut.actime = times[0].tv_sec;
	ut.modtime = times[1].tv_sec;
	if (utime(filename, &ut) < 0)
	perror("utime");
	#endif
	}


	int main(int argc, char **argv)
	{
	char line[2048];
	int c;
	int fd, ofd = -1;
	FILE in, out, *old = NULL;
	char outfn = NULL, newfn = NULL;
	int verbose = 0;
	int adjust_timestamp = 0;
	int got_atime = 0;
	struct stat stbuf;
	struct timeval tv[2];

	while ((c = getopt (argc, argv, "f:tv")) != EOF) {
	switch (c) {
	case 'f':
	in = fopen(optarg, "r");
	if (!in) {
	perror(optarg);
	exit(1);
	}
	parse_config_file(in);
	fclose(in);
	break;
	case 't':
	adjust_timestamp++;
	break;
	case 'v':
	verbose++;
	break;
	default:
	fprintf(stderr, "%s: [-f config-file] [file]\n",
	argv[0]);
	break;
	}
	}
	if (optind < argc) {
	in = fopen(argv[optind], "r");
	if (!in) {
	perror(argv[optind]);
	exit(1);
	}
	optind++;
	} else
	in = stdin;

	if (optind < argc) {
	outfn = argv[optind];
	newfn = (char *) malloc(strlen(outfn)+20);
	if (!newfn) {
	fprintf(stderr, "Memory error! Exiting.\n");
	exit(1);
	}
	strcpy(newfn, outfn);
	strcat(newfn, ".new");
	ofd = open(newfn, O_CREAT\|O_TRUNC\|O_RDWR, 0644);
	if (ofd < 0) {
	perror(newfn);
	exit(1);
	}
	out = fdopen(ofd, "w+");
	if (!out) {
	perror("fdopen");
	exit(1);
	}

	fd = open(outfn, O_RDONLY);
	if (fd > 0) {
	/* save the original atime, if possible */
	if (fstat(fd, &stbuf) == 0) {
	#if HAVE_STRUCT_STAT_ST_ATIM
	tv[0].tv_sec = stbuf.st_atim.tv_sec;
	tv[0].tv_usec = stbuf.st_atim.tv_nsec / 1000;
	#else
	tv[0].tv_sec = stbuf.st_atime;
	tv[0].tv_usec = 0;
	#endif
	got_atime = 1;
	}
	old = fdopen(fd, "r");
	if (!old)
	close(fd);
	}
	} else {
	out = stdout;
	outfn = 0;
	}

	while (!feof(in)) {
	if (fgets(line, sizeof(line), in) == NULL)
	break;
	substitute_line(line);
	fputs(line, out);
	}
	fclose(in);
	if (outfn) {
	fflush(out);
	rewind(out);
	if (old && compare_file(old, out)) {
	if (verbose)
	printf("No change, keeping %s.\n", outfn);
	if (adjust_timestamp) {
	if (verbose)
	printf("Updating modtime for %s\n", outfn);
	if (gettimeofday(&tv[1], NULL) < 0) {
	perror("gettimeofday");
	exit(1);
	}
	if (got_atime == 0)
	tv[0] = tv[1];
	else if (verbose)
	printf("Using original atime\n");
	set_utimes(outfn, fileno(old), tv);
	}
	if (ofd >= 0)
	(void) fchmod(ofd, 0444);
	fclose(out);
	if (unlink(newfn) < 0)
	perror("unlink");
	} else {
	if (verbose)
	printf("Creating or replacing %s.\n", outfn);
	if (ofd >= 0)
	(void) fchmod(ofd, 0444);
	fclose(out);
	if (old)
	fclose(old);
	old = NULL;
	if (rename(newfn, outfn) < 0) {
	perror("rename");
	exit(1);
	}
	}
	}
	if (old)
	fclose(old);
	if (newfn)
	free(newfn);
	return (0);
	}