From 05020632bc1cb10a84805143e19d01f7244059be Mon Sep 17 00:00:00 2001
From: Luis Gerhorst <privat@luisgerhorst.de>
Date: Thu, 13 May 2021 20:42:41 +0200
Subject: [PATCH] fp-based find-magic
---
src/task-find-magic | 2 +-
src/task_filter_magic.c | 67 ++++++++++++++++++++++++++++++++++-------
2 files changed, 57 insertions(+), 12 deletions(-)
diff --git a/src/task-find-magic b/src/task-find-magic
index a97489e..f3d77e6 100755
--- a/src/task-find-magic
+++ b/src/task-find-magic
@@ -6,4 +6,4 @@ args=${@:2}
src_dir=$(dirname "$(command -v $0)")
-find "${path}" | env -C "$src_dir" ./task_filter_magic ${args}
+find "${path}" | ${src_dir}/task_filter_magic ${args}
diff --git a/src/task_filter_magic.c b/src/task_filter_magic.c
index 45a0c7a..4194008 100644
--- a/src/task_filter_magic.c
+++ b/src/task_filter_magic.c
@@ -181,20 +181,17 @@ destroy:
return EXIT_SUCCESS;
}
-static char *safe_fgets(char *s, int size, FILE *stream) {
- char *res = fgets(s, size, stream);
- if (res == NULL && ferror(stream)) {
- perror("fgets");
- exit(EXIT_FAILURE);
- }
- return res;
-}
-
#define MAX_PATHLEN 512
static int filter_magic(size_t offset, const char *magic) {
+ int err;
+ size_t magic_size = strlen(magic) + 1;
+ char buf[magic_size];
+ buf[magic_size-1] = '\0';
+
while (true) {
char pathbuf[MAX_PATHLEN];
+ /* TODO: What if line too long? */
char *ptr = fgets(pathbuf, MAX_PATHLEN, stdin);
if (ptr == NULL) {
if (ferror(stdin)) {
@@ -206,9 +203,57 @@ static int filter_magic(size_t offset, const char *magic) {
}
}
- pathbuf[strlen(pathbuf)] = '\0';
-
+ /* Line must end with a newline. */
+ pathbuf[strlen(pathbuf)-1] = '\0';
log_debug("pathbuf = %s", pathbuf);
+
+ FILE *fp = fopen(pathbuf, "r");
+ if (!fp) {
+ perror(pathbuf);
+ return EXIT_FAILURE;
+ }
+
+ struct stat statbuf;
+ err = fstat(fileno(fp), &statbuf);
+ if (err != 0) {
+ log_debug("Skipping %s: Error fstat()ing file.", pathbuf);
+ goto fclose;
+ }
+
+ // handling only regular files and FIFOs
+ if (!S_ISREG(statbuf.st_mode) && !S_ISFIFO(statbuf.st_mode)) {
+ log_debug("Skipping %s: Mode %u is not a file.", pathbuf, statbuf.st_mode);
+ goto fclose;
+ }
+
+ if (statbuf.st_size < offset + magic_size-1) {
+ goto fclose;
+ }
+
+ if (offset) {
+ err = fseek(fp, offset, SEEK_SET);
+ if (err) {
+ perror("fseek");
+ return EXIT_FAILURE;
+ }
+ }
+
+ size_t nread = fread(buf, sizeof(char), magic_size-1, fp);
+ if (nread < magic_size-1) {
+ log_err("fread(%s) returned short item count", pathbuf);
+ return EXIT_FAILURE;
+ }
+
+ if (strcmp(magic, buf) == 0) {
+ printf("%s\n", pathbuf);
+ }
+
+ fclose:
+ err = fclose(fp);
+ if (err) {
+ perror("fclose");
+ return EXIT_FAILURE;
+ }
}
}
--
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