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-rw-r--r--ch8/8-05_fsize-extended.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/ch8/8-05_fsize-extended.c b/ch8/8-05_fsize-extended.c
new file mode 100644
index 0000000..c296104
--- /dev/null
+++ b/ch8/8-05_fsize-extended.c
@@ -0,0 +1,77 @@
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+
+/* The C Programming Language: 2nd Edition
+ *
+ * Exercise 8-5: Modify the fsize program to print the other information
+ * contained in the inode entry.
+ *
+ * Notes: The supplied header file examples don't really work well on a
+ * GNU/Linux system in 2022. :) This makes 8-5 the only exercise in the book
+ * that's broken enough to nearly require the standard library to complete.
+ * Despite lacking the homegrown headers, this exercise is still a good example
+ * of callbacks.
+ *
+ * Not all of the information within the stat struct is displayed by this
+ * program; this is mostly due to the information not being terribly useful
+ * on all systems. Modification time and permission information is relevant
+ * to all platforms.
+ */
+
+void fsize(char *);
+void dirwalk(char *, void (*fcn)(char *));
+
+int main(int argc, char **argv) {
+ if (argc == 1) {
+ fsize(".");
+ } else {
+ while (--argc > 0) {
+ fsize(*++argv);
+ }
+ }
+ return 0;
+}
+
+void fsize(char *name) {
+ struct stat stbuf;
+ if (stat(name, &stbuf) == -1) {
+ fprintf(stderr, "fsize: can't access %s\n", name);
+ return;
+ }
+ if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
+ dirwalk(name, fsize);
+ }
+ /*
+ * Size, Mode, UID, GID, ModifiedTime, FileName
+ */
+ printf("%8ld %6o %d %d %ld %s\n", stbuf.st_size, stbuf.st_mode, stbuf.st_uid, stbuf.st_gid, stbuf.st_mtime, name);
+}
+
+void dirwalk(char *dir, void (*fcn)(char *)) {
+ char name[PATH_MAX];
+ struct dirent *dp;
+ DIR *dfd;
+ if ((dfd = opendir(dir)) == NULL) {
+ fprintf(stderr, "dirwalk: can't open %s\n", dir);
+ return;
+ }
+ while ((dp = readdir(dfd)) != NULL) {
+ if (strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0) {
+ continue;
+ }
+ if (strlen(dir)+strlen(dp->d_name)+2 > sizeof (name)) {
+ fprintf(stderr, "dirwalk: name %s/%s too long\n", dir, dp->d_name);
+ } else {
+ sprintf(name, "%s/%s", dir, dp->d_name);
+ (*fcn)(name);
+ }
+ }
+ closedir(dfd);
+}