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tac: handle NULs properly. +145 bytes

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This commit is contained in:
Denis Vlasenko 2008-01-09 23:00:00 +00:00
parent d2c450ce81
commit de24bd960f
1 changed files with 35 additions and 11 deletions
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46
coreutils/tac.c
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@ -20,12 +20,17 @@
/* This is a NOEXEC applet. Be very careful! */
struct lstring {
int size;
char buf[];
};
int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tac_main(int argc, char **argv)
{
char **name;
FILE *f;
char *line;
struct lstring *line = NULL;
llist_t *list = NULL;
int retval = EXIT_SUCCESS;
@ -38,6 +43,8 @@ int tac_main(int argc, char **argv)
name++;
do {
int ch, i;
name--;
f = fopen_or_warn_stdin(*name);
if (f == NULL) {
@ -45,14 +52,26 @@ int tac_main(int argc, char **argv)
continue;
}
errno = 0;
/* FIXME: NUL bytes are mishandled. */
while ((line = xmalloc_fgets(f)) != NULL)
llist_add_to(&list, line);
/* xmalloc_fgets uses getc and returns NULL on error or EOF. */
/* It sets errno to ENOENT on EOF, but fopen_or_warn_stdin would */
/* catch this error so we can filter it out here. */
errno = i = 0;
do {
ch = fgetc(f);
if (ch != EOF) {
if (!(i & 0x7f))
/* Grow on every 128th char */
line = xrealloc(line, i + 0x7f + sizeof(int) + 1);
line->buf[i++] = ch;
}
if ((ch == '\n' || ch == EOF) && i) {
line = xrealloc(line, i + sizeof(int));
line->size = i;
llist_add_to(&list, line);
line = NULL;
i = 0;
}
} while (ch != EOF);
/* fgetc sets errno to ENOENT on EOF, but */
/* fopen_or_warn_stdin would catch this error */
/* so we can filter it out here. */
if (errno && errno != ENOENT) {
bb_simple_perror_msg(*name);
retval = EXIT_FAILURE;
@ -60,8 +79,13 @@ int tac_main(int argc, char **argv)
} while (name != argv);
while (list) {
printf("%s", list->data);
list = list->link;
line = (struct lstring *)list->data;
xwrite(STDOUT_FILENO, line->buf, line->size);
if (ENABLE_FEATURE_CLEAN_UP) {
free(llist_pop(&list));
} else {
list = list->link;
}
}
return retval;