From d1e063beb43e595680c65e3804d1f8ddff53373b Mon Sep 17 00:00:00 2001 From: Guido Guenther Date: Sat, 18 Nov 2006 23:48:07 +0100 Subject: Imported Debian version 0.3.8.8 --- e2fslib/util/subst.c | 374 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 374 insertions(+) create mode 100644 e2fslib/util/subst.c (limited to 'e2fslib/util/subst.c') diff --git a/e2fslib/util/subst.c b/e2fslib/util/subst.c new file mode 100644 index 0000000..7b7ba83 --- /dev/null +++ b/e2fslib/util/subst.c @@ -0,0 +1,374 @@ +/* + * subst.c --- substitution program + * + * Subst is used as a quicky program to do @ substitutions + * + */ + +#include +#include +#include +#include +#include +#include + +#ifdef HAVE_GETOPT_H +#include +#else +extern char *optarg; +extern int optind; +#endif + + +struct subst_entry { + char *name; + char *value; + struct subst_entry *next; +}; + +struct subst_entry *subst_table = 0; + +static int add_subst(char *name, char *value) +{ + struct subst_entry *ent = 0; + int retval; + + retval = ENOMEM; + 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) { + if (ent->name) + free(ent->name); + if (ent->value) + free(ent->value); + free(ent); + } + return retval; +} + +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, int 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; + int 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); + } + /* + * 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 : ""); +#endif + add_subst(ptr, cp); + } +} + +/* + * Return 0 if the files are different, 1 if the files are the same. + */ +static int compare_file(const char *outfn, const char *newfn) +{ + FILE *old_f, *new_f; + char oldbuf[2048], newbuf[2048], *oldcp, *newcp; + int retval; + + old_f = fopen(outfn, "r"); + if (!old_f) + return 0; + new_f = fopen(newfn, "r"); + if (!new_f) + return 0; + + 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; + } + } + fclose(old_f); + fclose(new_f); + return retval; +} + + + + +int main(int argc, char **argv) +{ + char line[2048]; + int c; + FILE *in, *out; + char *outfn = NULL, *newfn = NULL; + int verbose = 0; + + while ((c = getopt (argc, argv, "f:v")) != EOF) { + switch (c) { + case 'f': + in = fopen(optarg, "r"); + if (!in) { + perror(optarg); + exit(1); + } + parse_config_file(in); + fclose(in); + 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"); + out = fopen(newfn, "w"); + if (!out) { + perror(newfn); + exit(1); + } + } else { + out = stdout; + outfn = 0; + } + + while (!feof(in)) { + if (fgets(line, sizeof(line), in) == NULL) + break; + substitute_line(line); + fputs(line, out); + } + fclose(in); + fclose(out); + if (outfn) { + if (compare_file(outfn, newfn)) { + if (verbose) + printf("No change, keeping %s.\n", outfn); + unlink(newfn); + } else { + if (verbose) + printf("Creating or replacing %s.\n", outfn); + rename(newfn, outfn); + } + } + return (0); +} + + -- cgit v1.2.3