shared: rework env file reader

Implement this with a proper state machine, so that newlines and
escaped chars can appear in string assignments. This should bring the
parser much closer to shell.
This commit is contained in:
Lennart Poettering
2013-04-03 20:12:57 +02:00
parent 7f602784de
commit f73141d765
9 changed files with 442 additions and 151 deletions
+300 -121
View File
@@ -177,169 +177,348 @@ int read_full_file(const char *fn, char **contents, size_t *size) {
return 0;
}
int parse_env_file(
static int parse_env_file_internal(
const char *fname,
const char *separator, ...) {
const char *newline,
int (*push) (const char *key, char *value, void *userdata),
void *userdata) {
int r = 0;
char *contents = NULL, *p;
_cleanup_free_ char *contents = NULL, *key = NULL;
size_t key_alloc = 0, n_key = 0, value_alloc = 0, n_value = 0, last_whitespace = (size_t) -1;
char *p, *value = NULL;
int r;
enum {
PRE_KEY,
KEY,
PRE_EQUAL,
PRE_VALUE,
VALUE,
VALUE_ESCAPE,
SINGLE_QUOTE_VALUE,
SINGLE_QUOTE_VALUE_ESCAPE,
DOUBLE_QUOTE_VALUE,
DOUBLE_QUOTE_VALUE_ESCAPE,
COMMENT,
COMMENT_ESCAPE
} state = PRE_KEY;
assert(fname);
assert(separator);
assert(newline);
r = read_full_file(fname, &contents, NULL);
if (r < 0)
return r;
p = contents;
for (;;) {
const char *key = NULL;
for (p = contents; *p; p++) {
char c = *p;
p += strspn(p, separator);
p += strspn(p, WHITESPACE);
switch (state) {
if (!*p)
break;
if (!strchr(COMMENTS, *p)) {
va_list ap;
char **value;
va_start(ap, separator);
while ((key = va_arg(ap, char *))) {
size_t n;
char *v;
value = va_arg(ap, char **);
n = strlen(key);
if (!strneq(p, key, n) ||
p[n] != '=')
continue;
p += n + 1;
n = strcspn(p, separator);
if (n >= 2 &&
strchr(QUOTES, p[0]) &&
p[n-1] == p[0])
v = strndup(p+1, n-2);
else
v = strndup(p, n);
if (!v) {
case PRE_KEY:
if (strchr(COMMENTS, c))
state = COMMENT;
else if (!strchr(WHITESPACE, c)) {
state = KEY;
if (!greedy_realloc((void**) &key, &key_alloc, n_key+2)) {
r = -ENOMEM;
va_end(ap);
goto fail;
}
if (v[0] == '\0') {
/* return empty value strings as NULL */
free(v);
v = NULL;
key[n_key++] = c;
}
break;
case KEY:
if (strchr(newline, c)) {
state = PRE_KEY;
n_key = 0;
} else if (strchr(WHITESPACE, c))
state = PRE_EQUAL;
else if (c == '=')
state = PRE_VALUE;
else {
if (!greedy_realloc((void**) &key, &key_alloc, n_key+2)) {
r = -ENOMEM;
goto fail;
}
free(*value);
*value = v;
p += n;
r ++;
break;
key[n_key++] = c;
}
va_end(ap);
}
if (!key)
p += strcspn(p, separator);
break;
case PRE_EQUAL:
if (strchr(newline, c)) {
state = PRE_KEY;
n_key = 0;
} else if (c == '=')
state = PRE_VALUE;
else if (!strchr(WHITESPACE, c)) {
n_key = 0;
state = COMMENT;
}
break;
case PRE_VALUE:
if (strchr(newline, c)) {
state = PRE_KEY;
key[n_key] = 0;
if (value)
value[n_value] = 0;
r = push(key, value, userdata);
if (r < 0)
goto fail;
n_key = 0;
value = NULL;
value_alloc = n_value = 0;
} else if (c == '\'')
state = SINGLE_QUOTE_VALUE;
else if (c == '\"')
state = DOUBLE_QUOTE_VALUE;
else if (c == '\\')
state = VALUE_ESCAPE;
else if (!strchr(WHITESPACE, c)) {
state = VALUE;
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case VALUE:
if (strchr(newline, c)) {
state = PRE_KEY;
key[n_key] = 0;
if (value)
value[n_value] = 0;
/* Chomp off trailing whitespace */
if (last_whitespace != (size_t) -1)
value[last_whitespace] = 0;
r = push(key, value, userdata);
if (r < 0)
goto fail;
n_key = 0;
value = NULL;
value_alloc = n_value = 0;
} else if (c == '\\') {
state = VALUE_ESCAPE;
last_whitespace = (size_t) -1;
} else {
if (!strchr(WHITESPACE, c))
last_whitespace = (size_t) -1;
else if (last_whitespace == (size_t) -1)
last_whitespace = n_value;
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case VALUE_ESCAPE:
state = VALUE;
if (!strchr(newline, c)) {
/* Escaped newlines we eat up entirely */
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case SINGLE_QUOTE_VALUE:
if (c == '\'')
state = PRE_VALUE;
else if (c == '\\')
state = SINGLE_QUOTE_VALUE_ESCAPE;
else {
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case SINGLE_QUOTE_VALUE_ESCAPE:
state = SINGLE_QUOTE_VALUE;
if (!strchr(newline, c)) {
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case DOUBLE_QUOTE_VALUE:
if (c == '\"')
state = PRE_VALUE;
else if (c == '\\')
state = DOUBLE_QUOTE_VALUE_ESCAPE;
else {
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case DOUBLE_QUOTE_VALUE_ESCAPE:
state = DOUBLE_QUOTE_VALUE;
if (!strchr(newline, c)) {
if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case COMMENT:
if (c == '\\')
state = COMMENT_ESCAPE;
else if (strchr(newline, c))
state = PRE_KEY;
break;
case COMMENT_ESCAPE:
state = COMMENT;
break;
}
}
if (state == PRE_VALUE ||
state == VALUE ||
state == VALUE_ESCAPE ||
state == SINGLE_QUOTE_VALUE ||
state == SINGLE_QUOTE_VALUE_ESCAPE ||
state == DOUBLE_QUOTE_VALUE ||
state == DOUBLE_QUOTE_VALUE_ESCAPE) {
key[n_key] = 0;
if (value)
value[n_value] = 0;
r = push(key, value, userdata);
if (r < 0)
goto fail;
}
return 0;
fail:
free(contents);
free(value);
return r;
}
int load_env_file(const char *fname, char ***rl) {
static int parse_env_file_push(const char *key, char *value, void *userdata) {
const char *k;
va_list* ap = (va_list*) userdata;
va_list aq;
_cleanup_fclose_ FILE *f;
_cleanup_strv_free_ char **m = NULL;
_cleanup_free_ char *c = NULL;
va_copy(aq, *ap);
assert(fname);
assert(rl);
while ((k = va_arg(aq, const char *))) {
char **v;
/* This reads an environment file, but will not complain about
* any invalid assignments, that needs to be done by the
* caller */
v = va_arg(aq, char **);
f = fopen(fname, "re");
if (!f)
return -errno;
while (!feof(f)) {
char l[LINE_MAX], *p, *cs, *b;
if (!fgets(l, sizeof(l), f)) {
if (ferror(f))
return -errno;
/* The previous line was a continuation line?
* Let's process it now, before we leave the
* loop */
if (c)
goto process;
break;
if (streq(key, k)) {
va_end(aq);
free(*v);
*v = value;
return 1;
}
}
/* Is this a continuation line? If so, just append
* this to c, and go to next line right-away */
cs = endswith(l, "\\\n");
if (cs) {
*cs = '\0';
b = strappend(c, l);
if (!b)
return -ENOMEM;
va_end(aq);
free(c);
c = b;
continue;
}
free(value);
return 0;
}
/* If the previous line was a continuation line,
* append the current line to it */
if (c) {
b = strappend(c, l);
if (!b)
return -ENOMEM;
int parse_env_file(
const char *fname,
const char *newline, ...) {
free(c);
c = b;
}
va_list ap;
int r;
process:
p = strstrip(c ? c : l);
if (!newline)
newline = NEWLINE;
if (*p && !strchr(COMMENTS, *p)) {
_cleanup_free_ char *u;
int k;
va_start(ap, newline);
r = parse_env_file_internal(fname, newline, parse_env_file_push, &ap);
va_end(ap);
u = normalize_env_assignment(p);
if (!u)
return -ENOMEM;
return r;
}
k = strv_extend(&m, u);
if (k < 0)
return -ENOMEM;
}
static int load_env_file_push(const char *key, char *value, void *userdata) {
char ***m = userdata;
char *p;
int r;
free(c);
c = NULL;
p = strjoin(key, "=", strempty(value), NULL);
if (!p)
return -ENOMEM;
r = strv_push(m, p);
if (r < 0) {
free(p);
return r;
}
free(value);
return 0;
}
int load_env_file(const char *fname, const char *newline, char ***rl) {
char **m = NULL;
int r;
if (!newline)
newline = NEWLINE;
r = parse_env_file_internal(fname, newline, load_env_file_push, &m);
if (r < 0) {
strv_free(m);
return r;
}
*rl = m;
m = NULL;
return 0;
}
+1 -1
View File
@@ -29,5 +29,5 @@ int read_one_line_file(const char *fn, char **line);
int read_full_file(const char *fn, char **contents, size_t *size);
int parse_env_file(const char *fname, const char *separator, ...) _sentinel_;
int load_env_file(const char *fname, char ***l);
int load_env_file(const char *fname, const char *separator, char ***l);
int write_env_file(const char *fname, char **l);