8:21 a.m.
Add the perl file editing, mostly based in the virt-edit implementation.
This introduces a mild code duplication with edit_file_editor; will deal
with it in a later commit.
---
fish/file-edit.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
fish/file-edit.h | 11 ++++++
2 files changed, 121 insertions(+)
diff --git a/fish/file-edit.c b/fish/file-edit.c
index e2298eb..fa68626 100644
--- a/fish/file-edit.c
+++ b/fish/file-edit.c
@@ -159,6 +159,116 @@ edit_file_editor (guestfs_h *g, const char *filename, const char
*editor,
return 0;
}
+int
+edit_file_perl (guestfs_h *g, const char *filename, const char *perl_expr,
+ const char *backup_extension)
+{
+ CLEANUP_FREE char *tmpdir = guestfs_get_tmpdir (g);
+ CLEANUP_UNLINK_FREE char *tmpfilename = NULL;
+ char buf[256];
+ CLEANUP_FREE char *newname = NULL;
+ CLEANUP_FREE char *cmd = NULL;
+ CLEANUP_FREE char *outfile = NULL;
+ int r, fd;
+
+ /* Download the file and write it to a temporary. */
+ if (asprintf (&tmpfilename, "%s/libguestfsXXXXXX", tmpdir) == -1) {
+ perror ("asprintf");
+ return -1;
+ }
+
+ fd = mkstemp (tmpfilename);
+ if (fd == -1) {
+ perror ("mkstemp");
+ return -1;
+ }
+
+ snprintf (buf, sizeof buf, "/dev/fd/%d", fd);
+
+ if (guestfs_download (g, filename, buf) == -1) {
+ close (fd);
+ return -1;
+ }
+
+ if (close (fd) == -1) {
+ perror (tmpfilename);
+ return -1;
+ }
+
+ if (asprintf (&outfile, "%s.out", tmpfilename) == -1) {
+ perror ("asprintf");
+ return -1;
+ }
+
+ /* Pass the expression to Perl via the environment. This sidesteps
+ * any quoting problems with the already complex Perl command line.
+ */
+ setenv ("virt_edit_expr", perl_expr, 1);
+
+ /* Call out to a canned Perl script. */
+ if (asprintf (&cmd,
+ "perl -e '"
+ "$lineno = 0; "
+ "$expr = $ENV{virt_edit_expr}; "
+ "while (<STDIN>) { "
+ " $lineno++; "
+ " eval $expr; "
+ " die if $@; "
+ " print STDOUT $_ or die \"print: $!\"; "
+ "} "
+ "close STDOUT or die \"close: $!\"; "
+ "' < %s > %s",
+ tmpfilename, outfile) == -1) {
+ perror ("asprintf");
+ return -1;
+ }
+
+ r = system (cmd);
+ if (r == -1 || WEXITSTATUS (r) != 0)
+ return -1;
+
+ if (rename (outfile, tmpfilename) == -1) {
+ perror ("rename");
+ return -1;
+ }
+
+ /* Upload to a new file in the same directory, so if it fails we
+ * don't end up with a partially written file. Give the new file
+ * a completely random name so we have only a tiny chance of
+ * overwriting some existing file.
+ */
+ newname = generate_random_name (filename);
+ if (!newname)
+ return -1;
+
+ /* Write new content. */
+ if (guestfs_upload (g, tmpfilename, newname) == -1)
+ return -1;
+
+ /* Set the permissions, UID, GID and SELinux context of the new
+ * file to match the old file (RHBZ#788641).
+ */
+ if (guestfs_copy_attributes (g, filename, newname,
+ GUESTFS_COPY_ATTRIBUTES_ALL, 1, -1) == -1)
+ return -1;
+
+ /* Backup or overwrite the file. */
+ if (backup_extension) {
+ CLEANUP_FREE char *backupname = NULL;
+
+ backupname = generate_backup_name (filename, backup_extension);
+ if (backupname == NULL)
+ return -1;
+
+ if (guestfs_mv (g, filename, backupname) == -1)
+ return -1;
+ }
+ if (guestfs_mv (g, newname, filename) == -1)
+ return -1;
+
+ return 0;
+}
+
static char
random_char (void)
{
diff --git a/fish/file-edit.h b/fish/file-edit.h
index 1d401c6..98fc453 100644
--- a/fish/file-edit.h
+++ b/fish/file-edit.h
@@ -32,4 +32,15 @@
extern int edit_file_editor (guestfs_h *g, const char *filename,
const char *editor, const char *backup_extension);
+/**
+ * Edit 'filename' running the specified 'perl_expr' using Perl.
+ * If 'backup_extension' is not null, then a copy of 'filename' is saved
+ * with 'backup_extension' appended to its file name.
+ *
+ * Returns -1 for failure, 0 otherwise (on success).
+ */
+extern int edit_file_perl (guestfs_h *g, const char *filename,
+ const char *perl_expr,
+ const char *backup_extension);
+
#endif
--
1.9.3