Commit 3b1ec9fb8197197d5e3bcca3a05e82d4f50f11bc
Committed by
Sam Ravnborg
Sam Ravnborg
1 parent
efddd79512
kbuild: gen_init_cpio expands shell variables in file names
Modify gen_init_cpio so that lines that specify files can contain
what looks like a shell variable that's expanded during processing.
For example:
file /sbin/kinit ${RFS_BASE}/usr/src/klibc/kinit/kinit 0755 0 0
given RFS_BASE is "/some/directory" in the environment
would be expanded to
file /sbin/kinit /some/directory/usr/src/klibc/kinit/kinit 0755 0 0
If several environment variables appear in a line, they are all expanded
with processing happening from left to right.
Undefined variables expand to a null string.
Syntax errors stop processing, letting the existing error handling
show the user offending line.
This patch helps embedded folks who frequently create several
RFS directories and then switch between them as they're tuning
an initramfs.
Signed-off-by: gene.sally@timesys.com
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Showing 1 changed file with 27 additions and 1 deletions Side-by-side Diff
usr/gen_init_cpio.c
| ... | ... | @@ -370,6 +370,30 @@ |
| 370 | 370 | return rc; |
| 371 | 371 | } |
| 372 | 372 | |
| 373 | +static char *cpio_replace_env(char *new_location) | |
| 374 | +{ | |
| 375 | + char expanded[PATH_MAX + 1]; | |
| 376 | + char env_var[PATH_MAX + 1]; | |
| 377 | + char *start; | |
| 378 | + char *end; | |
| 379 | + | |
| 380 | + for (start = NULL; (start = strstr(new_location, "${")); ) { | |
| 381 | + end = strchr(start, '}'); | |
| 382 | + if (start < end) { | |
| 383 | + *env_var = *expanded = '\0'; | |
| 384 | + strncat(env_var, start + 2, end - start - 2); | |
| 385 | + strncat(expanded, new_location, start - new_location); | |
| 386 | + strncat(expanded, getenv(env_var), PATH_MAX); | |
| 387 | + strncat(expanded, end + 1, PATH_MAX); | |
| 388 | + strncpy(new_location, expanded, PATH_MAX); | |
| 389 | + } else | |
| 390 | + break; | |
| 391 | + } | |
| 392 | + | |
| 393 | + return new_location; | |
| 394 | +} | |
| 395 | + | |
| 396 | + | |
| 373 | 397 | static int cpio_mkfile_line(const char *line) |
| 374 | 398 | { |
| 375 | 399 | char name[PATH_MAX + 1]; |
| ... | ... | @@ -415,7 +439,8 @@ |
| 415 | 439 | } else { |
| 416 | 440 | dname = name; |
| 417 | 441 | } |
| 418 | - rc = cpio_mkfile(dname, location, mode, uid, gid, nlinks); | |
| 442 | + rc = cpio_mkfile(dname, cpio_replace_env(location), | |
| 443 | + mode, uid, gid, nlinks); | |
| 419 | 444 | fail: |
| 420 | 445 | if (dname_len) free(dname); |
| 421 | 446 | return rc; |
| ... | ... | @@ -439,6 +464,7 @@ |
| 439 | 464 | "\n" |
| 440 | 465 | "<name> name of the file/dir/nod/etc in the archive\n" |
| 441 | 466 | "<location> location of the file in the current filesystem\n" |
| 467 | + " expands shell variables quoted with ${}\n" | |
| 442 | 468 | "<target> link target\n" |
| 443 | 469 | "<mode> mode/permissions of the file\n" |
| 444 | 470 | "<uid> user id (0=root)\n" |