sed: correctly handle 'w FILE' commands writing to the same file

function                                             old     new   delta
sed_xfopen_w                                           -      84     +84

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2022-01-04 19:42:36 +01:00
parent ed2af2e82d
commit 286b33721d
2 changed files with 38 additions and 2 deletions

View File

@ -97,6 +97,12 @@ enum {
OPT_in_place = 1 << 0, OPT_in_place = 1 << 0,
}; };
struct sed_FILE {
struct sed_FILE *next; /* Next (linked list, NULL terminated) */
const char *fname;
FILE *fp;
};
/* Each sed command turns into one of these structures. */ /* Each sed command turns into one of these structures. */
typedef struct sed_cmd_s { typedef struct sed_cmd_s {
/* Ordered by alignment requirements: currently 36 bytes on x86 */ /* Ordered by alignment requirements: currently 36 bytes on x86 */
@ -151,6 +157,11 @@ struct globals {
/* linked list of append lines */ /* linked list of append lines */
llist_t *append_head; llist_t *append_head;
/* linked list of FILEs opened for 'w' and s///w'.
* Needed to handle duplicate fnames: sed '/a/w F;/b/w F'
*/
struct sed_FILE *FILE_head;
char *add_cmd_line; char *add_cmd_line;
struct pipeline { struct pipeline {
@ -211,6 +222,22 @@ static void sed_free_and_close_stuff(void)
void sed_free_and_close_stuff(void); void sed_free_and_close_stuff(void);
#endif #endif
static FILE *sed_xfopen_w(const char *fname)
{
struct sed_FILE **pp = &G.FILE_head;
struct sed_FILE *cur;
while ((cur = *pp) != NULL) {
if (strcmp(cur->fname, fname) == 0)
return cur->fp;
pp = &cur->next;
}
*pp = cur = xzalloc(sizeof(*cur));
/*cur->next = NULL; - already is */
cur->fname = xstrdup(fname);
cur->fp = xfopen_for_write(fname);
return cur->fp;
}
/* If something bad happens during -i operation, delete temp file */ /* If something bad happens during -i operation, delete temp file */
static void cleanup_outname(void) static void cleanup_outname(void)
@ -446,7 +473,7 @@ static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
{ {
char *fname; char *fname;
idx += parse_file_cmd(/*sed_cmd,*/ substr+idx+1, &fname); idx += parse_file_cmd(/*sed_cmd,*/ substr+idx+1, &fname);
sed_cmd->sw_file = xfopen_for_write(fname); sed_cmd->sw_file = sed_xfopen_w(fname);
sed_cmd->sw_last_char = '\n'; sed_cmd->sw_last_char = '\n';
free(fname); free(fname);
break; break;
@ -561,7 +588,7 @@ static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
} }
cmdstr += parse_file_cmd(/*sed_cmd,*/ cmdstr, &sed_cmd->string); cmdstr += parse_file_cmd(/*sed_cmd,*/ cmdstr, &sed_cmd->string);
if (sed_cmd->cmd == 'w') { if (sed_cmd->cmd == 'w') {
sed_cmd->sw_file = xfopen_for_write(sed_cmd->string); sed_cmd->sw_file = sed_xfopen_w(sed_cmd->string);
sed_cmd->sw_last_char = '\n'; sed_cmd->sw_last_char = '\n';
} }
} }

View File

@ -405,6 +405,15 @@ testing "sed ^ OR not^" \
"" \ "" \
"abca\n" "abca\n"
# This only works if file name is exactly the same.
# For example, w FILE; w ./FILE won't work.
testing "sed understands duplicate file name" \
"sed -n -e '/a/w sed.output' -e '/c/w sed.output' 2>&1 && cat sed.output && rm sed.output" \
"a\nc\n" \
"" \
"a\nb\nc\n"
# testing "description" "commands" "result" "infile" "stdin" # testing "description" "commands" "result" "infile" "stdin"
exit $FAILCOUNT exit $FAILCOUNT