diff options
Diffstat (limited to 'posix/wordexp.c')
| -rw-r--r-- | posix/wordexp.c | 70 |
1 files changed, 48 insertions, 22 deletions
diff --git a/posix/wordexp.c b/posix/wordexp.c index 942a9ac..7fc21f5 100644 --- a/posix/wordexp.c +++ b/posix/wordexp.c @@ -74,6 +74,7 @@ static int eval_expr (char *expr, long int *result) internal_function; #define W_CHUNK (100) +/* Result of w_newword will be ignored if it the last word. */ static inline char * w_newword (size_t *actlen, size_t *maxlen) { @@ -136,6 +137,20 @@ w_addmem (char *buffer, size_t *actlen, size_t *maxlen, const char *str, } +/* Result of w_emptyword will not be ignored even if it is the last. */ +static inline char * +w_emptyword (size_t *actlen, size_t *maxlen) +{ + char *word = malloc (1 + W_CHUNK); + *maxlen = W_CHUNK; + *actlen = 0; + + if (word) + *word = '\0'; + + return word; +} + static char * internal_function w_addstr (char *buffer, size_t *actlen, size_t *maxlen, const char *str) @@ -811,6 +826,7 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, int i; char *buffer; pid_t pid; + int keep_empty_word = 0; /* Don't fork() unless necessary */ if (!comm || !*comm) @@ -911,6 +927,11 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, if (strchr (ifs_white, buffer[i]) == NULL) { /* Current character is IFS but not whitespace */ + + /* After this delimiter, another field must result. + * Make a note. */ + keep_empty_word = 1; + if (copying == 2) { /* current character @@ -935,25 +956,12 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, if (copying != 1) continue; - /* End of field (search for non-IFS afterwards) */ + /* End of field (search for non-ws IFS afterwards) */ copying = 2; } /* First IFS white space, or IFS non-whitespace. - * Delimit the field. */ - if (!*word) - { - /* This field is null, so make it an empty string */ - *word = w_addchar (*word, word_length, max_length, 0); - if (*word == NULL) - { - __kill (pid, SIGKILL); - __waitpid (pid, NULL, 0); - __close (fildes[0]); - return WRDE_NOSPACE; - } - } - + * Delimit the field. Nulls are converted by w_addword. */ if (w_addword (pwordexp, *word) == WRDE_NOSPACE) { __kill (pid, SIGKILL); @@ -962,13 +970,20 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, return WRDE_NOSPACE; } - *word = w_newword (word_length, max_length); + if (keep_empty_word) + *word = w_emptyword (word_length, max_length); + else + *word = w_newword (word_length, max_length); /* fall back round the loop.. */ } else { /* Not IFS character */ copying = 1; + + if (buffer[i] != '\n') + keep_empty_word = 0; + *word = w_addchar (*word, word_length, max_length, buffer[i]); if (*word == NULL) @@ -985,7 +1000,18 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, /* Bash chops off trailing newlines, which seems sensible. */ while (*word_length > 0 && (*word)[*word_length - 1] == '\n') - (*word)[--*word_length] = '\0'; + { + (*word)[--*word_length] = '\0'; + + /* If the last word was entirely newlines, and the previous word + * wasn't delimited with IFS non-whitespace, turn it into a new word + * which can be ignored if there's nothing following it. */ + if (!keep_empty_word && *word_length == 0) + { + free (*word); + *word = w_newword (word_length, max_length); + } + } __close (fildes[0]); return 0; @@ -1723,7 +1749,7 @@ envsubst: free (value); if (value_copy == NULL) - return WRDE_NOSPACE; + goto no_space; do { @@ -1736,10 +1762,10 @@ envsubst: if (w_addword (pwordexp, *word) == WRDE_NOSPACE) { free (value_copy); - return WRDE_NOSPACE; + goto no_space; } - *word = w_newword (word_length, max_length); + *word = w_emptyword (word_length, max_length); } /* Skip IFS whitespace before the field */ @@ -1773,7 +1799,7 @@ envsubst: if (*word == NULL && *field_begin != '\0') { free (value_copy); - return WRDE_NOSPACE; + goto no_space; } field_begin = next_field; @@ -2217,7 +2243,7 @@ wordexp (const char *words, wordexp_t *pwordexp, int flags) /* End of string */ /* There was a word separator at the end */ - if (word == NULL) + if (word == NULL) /* i.e. w_newword */ return 0; /* There was no field separator at the end */ |