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authorSally, Gene <Gene.Sally@timesys.com>2008-10-29 09:54:17 -0400
committerSam Ravnborg <sam@ravnborg.org>2008-12-03 21:32:03 +0100
commit3b1ec9fb8197197d5e3bcca3a05e82d4f50f11bc (patch)
tree4581dc3493883f00abb0c3b61e3576edf1032197 /usr
parentefddd79512cc582675004bfdf7e66585198b38f9 (diff)
downloadkernel-3b1ec9fb8197197d5e3bcca3a05e82d4f50f11bc.tar.gz
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 ${RFS_BASE}/usr/src/klibc/kinit/kinit 0755 0 0 given RFS_BASE is "/some/directory" in the environment would be expanded to file /sbin/kinit /some/directory/usr/src/klibc/kinit/kinit 0755 0 0 If several environment variables appear in a line, they are all expanded with processing happening from left to right. Undefined variables expand to a null string. Syntax errors stop processing, letting the existing error handling show the user offending line. This patch helps embedded folks who frequently create several RFS directories and then switch between them as they're tuning an initramfs. Signed-off-by: gene.sally@timesys.com Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'usr')
-rw-r--r--usr/gen_init_cpio.c28
1 files changed, 27 insertions, 1 deletions
diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c
index 7abc07f0fcd2..f1d3fe34176a 100644
--- a/usr/gen_init_cpio.c
+++ b/usr/gen_init_cpio.c
@@ -370,6 +370,30 @@ error:
return rc;
}
+static char *cpio_replace_env(char *new_location)
+{
+ char expanded[PATH_MAX + 1];
+ char env_var[PATH_MAX + 1];
+ char *start;
+ char *end;
+
+ for (start = NULL; (start = strstr(new_location, "${")); ) {
+ end = strchr(start, '}');
+ if (start < end) {
+ *env_var = *expanded = '\0';
+ strncat(env_var, start + 2, end - start - 2);
+ strncat(expanded, new_location, start - new_location);
+ strncat(expanded, getenv(env_var), PATH_MAX);
+ strncat(expanded, end + 1, PATH_MAX);
+ strncpy(new_location, expanded, PATH_MAX);
+ } else
+ break;
+ }
+
+ return new_location;
+}
+
+
static int cpio_mkfile_line(const char *line)
{
char name[PATH_MAX + 1];
@@ -415,7 +439,8 @@ static int cpio_mkfile_line(const char *line)
} else {
dname = name;
}
- rc = cpio_mkfile(dname, location, mode, uid, gid, nlinks);
+ rc = cpio_mkfile(dname, cpio_replace_env(location),
+ mode, uid, gid, nlinks);
fail:
if (dname_len) free(dname);
return rc;
@@ -439,6 +464,7 @@ void usage(const char *prog)
"\n"
"<name> name of the file/dir/nod/etc in the archive\n"
"<location> location of the file in the current filesystem\n"
+ " expands shell variables quoted with ${}\n"
"<target> link target\n"
"<mode> mode/permissions of the file\n"
"<uid> user id (0=root)\n"