* subst.c --- substitution program
*
* Subst is used as a quicky program to do @ substitutions
- *
+ *
*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <utime.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
+#else
+extern char *optarg;
+extern int optind;
#endif
static int add_subst(char *name, char *value)
{
struct subst_entry *ent = 0;
- int retval;
-
- retval = ENOMEM;
- ent = malloc(sizeof(struct subst_entry));
+
+ ent = (struct subst_entry *) malloc(sizeof(struct subst_entry));
if (!ent)
goto fail;
- ent->name = malloc(strlen(name)+1);
+ ent->name = (char *) malloc(strlen(name)+1);
if (!ent->name)
goto fail;
- ent->value = malloc(strlen(value)+1);
+ ent->value = (char *) malloc(strlen(value)+1);
if (!ent->value)
goto fail;
strcpy(ent->name, name);
return 0;
fail:
if (ent) {
- if (ent->name)
- free(ent->name);
- if (ent->value)
- free(ent->value);
+ free(ent->name);
free(ent);
}
- return retval;
+ return ENOMEM;
}
static struct subst_entry *fetch_subst_entry(char *name)
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[128];
- int len, replace_len;
+ char *replace_name;
+ size_t len;
+ /*
+ * Expand all @FOO@ substitutions
+ */
ptr = line;
while (ptr) {
name_ptr = strchr(ptr, '@');
if (!name_ptr)
- break;
- end_ptr = strchr(name_ptr+1, '@');
+ 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 - 1;
- memcpy(replace_name, name_ptr+1, len);
- replace_name[len] = 0;
+ 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",
+ fprintf(stderr, "Unfound expansion: '%s'\n",
replace_name);
ptr = end_ptr + 1;
continue;
fprintf(stderr, "Replace name = '%s' with '%s'\n",
replace_name, ent->value);
#endif
- replace_len = strlen(ent->value);
- if (replace_len != len+2)
- memmove(end_ptr+(replace_len-len-2), end_ptr,
- strlen(end_ptr)+1);
- memcpy(name_ptr, ent->value, replace_len);
- ptr = name_ptr;
+ 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, '$');
+ if (!replace_name) {
+ ptr = name_ptr;
+ continue;
+ }
+ ent = fetch_subst_entry(replace_name);
+ if (!ent) {
+ ptr = end_ptr + 1;
+ continue;
+ }
+#if 0
+ fprintf(stderr, "Replace name = '%s' with '%s'\n",
+ replace_name, ent->value);
+#endif
+ ptr = name_ptr-2;
+ replace_string(ptr, end_ptr, ent->value);
}
}
/*
* Ignore future extensions
*/
- if (*ptr == '$')
+ if (*ptr == '@')
continue;
/*
* Parse substitutions
if (!isspace(*cp))
break;
#if 0
- printf("Substitute: '%s' for '%s'\n", ptr, cp);
+ printf("Substitute: '%s' for '%s'\n", ptr, cp ? cp : "<NULL>");
#endif
add_subst(ptr, cp);
}
*/
static int compare_file(const char *outfn, const char *newfn)
{
- FILE *old, *new;
+ FILE *old_f, *new_f;
char oldbuf[2048], newbuf[2048], *oldcp, *newcp;
int retval;
- old = fopen(outfn, "r");
- if (!old)
+ old_f = fopen(outfn, "r");
+ if (!old_f)
return 0;
- new = fopen(newfn, "r");
- if (!new)
+ new_f = fopen(newfn, "r");
+ if (!new_f) {
+ fclose(old_f);
return 0;
+ }
while (1) {
- oldcp = fgets(oldbuf, sizeof(oldbuf), old);
- newcp = fgets(newbuf, sizeof(newbuf), new);
+ oldcp = fgets(oldbuf, sizeof(oldbuf), old_f);
+ newcp = fgets(newbuf, sizeof(newbuf), new_f);
if (!oldcp && !newcp) {
retval = 1;
break;
break;
}
}
+ fclose(old_f);
+ fclose(new_f);
return retval;
}
-
int main(int argc, char **argv)
FILE *in, *out;
char *outfn = NULL, *newfn = NULL;
int verbose = 0;
-
- while ((c = getopt (argc, argv, "f:v")) != EOF) {
+ int adjust_timestamp = 0;
+ struct stat stbuf;
+ struct utimbuf ut;
+
+ while ((c = getopt (argc, argv, "f:tv")) != EOF) {
switch (c) {
case 'f':
in = fopen(optarg, "r");
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",
+ fprintf(stderr, "%s: [-f config-file] [file]\n",
argv[0]);
break;
}
optind++;
} else
in = stdin;
-
+
if (optind < argc) {
outfn = argv[optind];
- newfn = malloc(strlen(outfn)+20);
+ newfn = (char *) malloc(strlen(outfn)+20);
if (!newfn) {
fprintf(stderr, "Memory error! Exiting.\n");
exit(1);
out = stdout;
outfn = 0;
}
-
+
while (!feof(in)) {
if (fgets(line, sizeof(line), in) == NULL)
break;
fclose(in);
fclose(out);
if (outfn) {
+ struct stat st;
if (compare_file(outfn, newfn)) {
if (verbose)
printf("No change, keeping %s.\n", outfn);
+ if (adjust_timestamp) {
+ if (stat(outfn, &stbuf) == 0) {
+ if (verbose)
+ printf("Updating modtime for %s\n", outfn);
+ ut.actime = stbuf.st_atime;
+ ut.modtime = time(0);
+ if (utime(outfn, &ut) < 0)
+ perror("utime");
+ }
+ }
unlink(newfn);
} else {
if (verbose)
printf("Creating or replacing %s.\n", outfn);
rename(newfn, outfn);
}
+ /* set read-only to alert user it is a generated file */
+ if (stat(outfn, &st) == 0)
+ chmod(outfn, st.st_mode & ~0222);
}
return (0);
}
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff