1 files changed, 71 insertions, 1 deletions

diff --git a/lib/fs.c b/lib/fs.c
index 0cdda41..98a18e6 100644
--- a/lib/fs.c
+++ b/lib/fs.c
@@ -764,4 +764,74 @@ char **file_readlines(const char *filename, size_t start, size_t limit, ReaderFn
         fclose(fp);
     }
     return result;
-}
\ No newline at end of file
+}
+
+/**
+ * Determine whether `pattern` is present within a file
+ * @param filename
+ * @param pattern
+ * @return 0=found, 1=not found, -1=OS error
+ */
+int find_in_file(const char *filename, const char *pattern) {
+    int result = 1;  // default "not found"
+
+    FILE *fp = fopen(filename, "rb");
+    if (!fp) {
+        return -1;
+    }
+
+    long int file_len = get_file_size(filename);
+    if (file_len == -1) {
+        fclose(fp);
+        return -1;
+    }
+    char *buffer = (char *)calloc((size_t) file_len, sizeof(char));
+    if (!buffer) {
+        fclose(fp);
+        return -1;
+    }
+    size_t pattern_len = strlen(pattern);
+
+    fread(buffer, (size_t) file_len, sizeof(char), fp);
+    fclose(fp);
+
+    for (size_t i = 0; i < (size_t) file_len; i++) {
+        if (memcmp(&buffer[i], pattern, pattern_len) == 0) {
+            result = 0;  // found
+            break;
+        }
+    }
+    free(buffer);
+    return result;
+}
+
+/**
+ * Get the full path of a shell command
+ * @param program
+ * @return success=absolute path to program, failure=NULL
+ */
+char *find_executable(const char *program) {
+    int found = 0;
+    char *result = NULL;
+    char *env_path = NULL;
+    env_path = getenv("PATH");
+    if (!env_path) {
+        return NULL;
+    }
+    char **search_paths = split(env_path, ":");
+
+    char buf[PATH_MAX];
+    for (int i = 0; search_paths[i] != NULL; i++) {
+        sprintf(buf, "%s%c%s", search_paths[i], DIRSEP, program);
+        if (access(buf, F_OK | X_OK) == 0) {
+            found = 1;
+            break;
+        }
+        memset(buf, '\0', sizeof(buf));
+    }
+    if (found) {
+        result = strdup(buf);
+    }
+    split_free(search_paths);
+    return result;
+}