diff options
Diffstat (limited to 'ch8')
-rw-r--r-- | ch8/8-05_fsize-extended.c | 77 |
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); +} |