8c5da0323
Denys Vlasenko
2021-06-25
Subject
awk: more efficient -f FILE, document what "some trick in next_token" is
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
editors/awk.c+24 -9
| @@ -1217,6 +1217,8 @@ static uint32_t next_token(uint32_t expected) | |
| if (!isalnum_(*p)) | |
| syntax_error(EMSG_UNEXP_TOKEN); /* no */ | |
| /* yes */ | |
| + | /* "move name one char back" trick: we need a byte for NUL terminator */ |
| + | /* NB: this results in argv[i][-1] being used (!!!) in e.g. "awk -e 'NAME'" case */ |
| t_string = --p; | |
| while (isalnum_(*++p)) { | |
| p[-1] = *p; | |
| @@ -3345,7 +3347,7 @@ int awk_main(int argc UNUSED_PARAM, char **argv) | |
| #if ENABLE_FEATURE_AWK_GNU_EXTENSIONS | |
| llist_t *list_e = NULL; | |
| #endif | |
| - | int i, j; |
| + | int i; |
| var *v; | |
| var tv; | |
| char **envp; | |
| @@ -3417,30 +3419,43 @@ int awk_main(int argc UNUSED_PARAM, char **argv) | |
| bb_show_usage(); | |
| } | |
| while (list_f) { | |
| - | char *s = NULL; |
| - | FILE *from_file; |
| + | int fd; |
| + | char *s; |
| g_progname = llist_pop(&list_f); | |
| - | from_file = xfopen_stdin(g_progname); |
| - | /* one byte is reserved for some trick in next_token */ |
| - | for (i = j = 1; j > 0; i += j) { |
| - | s = xrealloc(s, i + 4096); |
| - | j = fread(s + i, 1, 4094, from_file); |
| + | fd = xopen_stdin(g_progname); |
| + | /* 1st byte is reserved for "move name one char back" trick in next_token */ |
| + | i = 1; |
| + | s = NULL; |
| + | for (;;) { |
| + | int sz; |
| + | s = xrealloc(s, i + 1000); |
| + | sz = safe_read(fd, s + i, 1000); |
| + | if (sz <= 0) |
| + | break; |
| + | i += sz; |
| } | |
| + | s = xrealloc(s, i + 1); /* trim unused 999 bytes */ |
| s[i] = '\0'; | |
| - | fclose(from_file); |
| + | close(fd); |
| parse_program(s + 1); | |
| free(s); | |
| } | |
| g_progname = "cmd. line"; | |
| #if ENABLE_FEATURE_AWK_GNU_EXTENSIONS | |
| while (list_e) { | |
| + | /* NB: "move name one char back" trick in next_token |
| + | * can use argv[i][-1] here. |
| + | */ |
| parse_program(llist_pop(&list_e)); | |
| } | |
| #endif | |
| if (!(opt & (OPT_f | OPT_e))) { | |
| if (!*argv) | |
| bb_show_usage(); | |
| + | /* NB: "move name one char back" trick in next_token |
| + | * can use argv[i][-1] here. |
| + | */ |
| parse_program(*argv++); | |
| } | |