FreeCalypso > hg > freecalypso-tools
view ffstools/tiffs-rd/ls.c @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Feb 2019 00:00:19 +0000 |
parents | e7502631a0f9 |
children | 1f27fc13eab7 |
line wrap: on
line source
/* * This C module implements the ls and lsino commands. */ #include <sys/types.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include "types.h" #include "struct.h" #include "globals.h" #include "pathname.h" static void segment_size_callback(inf, opaque) struct inode_info *inf; u_long opaque; { size_t *accump = (size_t *) opaque; struct chunkinfo chi; size_extra_chunk(inf, &chi); *accump += chi.len; } size_t get_file_size(seghead_ino, deleted) { struct chunkinfo chi; size_t accum; size_head_chunk(inode_info[seghead_ino], &chi); accum = chi.len; iterate_seg_file(seghead_ino, segment_size_callback, (u_long) &accum, deleted, 0); return(accum); } static void segment_ls_callback(inf, opaque) struct inode_info *inf; u_long opaque; { struct chunkinfo chi; size_extra_chunk(inf, &chi); if (verbose2 > 1) printf("seg #%04x @%08x length=%lu\n", inf->ino, inf->offset, (u_long) chi.len); else printf("seg #%04x length=%lu\n", inf->ino, (u_long) chi.len); } ls_seg_file(seghead_ino, deleted) { struct inode_info *inf = inode_info[seghead_ino]; struct chunkinfo chi; size_head_chunk(inf, &chi); printf("%lu bytes in seghead", (u_long) chi.len); if (verbose2 > 1) printf(", starting at offset %lx", (u_long)(inf->byte_after_name - image)); putchar('\n'); iterate_seg_file(seghead_ino, segment_ls_callback, 0L, deleted, verbose2 > 1); } void ls_tree_callback(pathname, ino, depth) char *pathname; { struct inode_info *inf = inode_info[ino]; u_long size; char readonly; if (inf->type & 0x10) readonly = ' '; else readonly = 'r'; switch (inf->type) { case 0xE1: case 0xF1: size = get_file_size(ino, 0); printf("f%c %7lu %s\n", readonly, size, pathname); if (verbose2) ls_seg_file(ino, 0); return; case 0xE2: case 0xF2: printf("d%c %s\n", readonly, pathname); return; case 0xE3: case 0xF3: printf("l%c %s\n", readonly, pathname); return; default: fprintf(stderr, "BUG: bad inode byte %02X reached ls_tree_callback()\n", inf->type); exit(1); } } ls_by_pathname(pathname) char *pathname; { int ino; struct inode_info *inf; char *type; printf("%s\n", pathname); ino = find_pathname(pathname); printf("inode #%x\n", ino); inf = inode_info[ino]; switch (inf->type) { case 0xE1: type = "read-only file"; break; case 0xF1: type = "file"; break; case 0xF2: type = "directory"; break; case 0xF3: type = "symlink"; break; default: type = "???"; } printf("object type %02X (%s)\n", inf->type, type); if (!validate_obj_name(ino, ino == root_inode)) { printf("No valid object name in the chunk!\n"); exit(1); } printf("object name: %s\n", inf->dataptr); if (inf->type == 0xF1 || inf->type == 0xE1) { printf("total size: %lu bytes\n", (u_long) get_file_size(ino, 0)); if (verbose2) ls_seg_file(ino, 0); } putchar('\n'); } cmd_ls(argc, argv) char **argv; { extern int optind; int c; read_ffs_image(); find_inode_block(); alloc_inode_table(); find_root_inode(); optind = 0; while ((c = getopt(argc, argv, "v")) != EOF) switch (c) { case 'v': verbose2++; continue; default: fprintf(stderr, "usage: ls [-v[v]] [pathname...]\n"); exit(1); } if (optind >= argc) { traverse_visible_tree(ls_tree_callback); exit(0); } for (; optind < argc; optind++) ls_by_pathname(argv[optind]); exit(0); } lsino_all() { int ino, last_ino = 0; struct inode_info *inf; char pathname[PATHNAME_BUF_SIZE], typech; int pathstat; char descend_str[8], sibling_str[8]; for (ino = 1; ino < inode_limit; ino++) { if (!validate_inode(ino)) continue; if (ino != last_ino + 1) printf("GAP in inode numbers\n"); inf = inode_info[ino]; pathstat = pathname_of_inode(ino, pathname); if (pathstat < 0) strcpy(pathname, "-nopath-"); switch (inf->type) { case 0x00: typech = '~'; break; case 0xE1: case 0xF1: typech = 'f'; break; case 0xF2: typech = 'd'; break; case 0xF3: typech = 'l'; break; case 0xF4: typech = '.'; break; default: typech = '?'; } printf("#%04x %c %s\n", ino, typech, pathname); if (inf->type && !(inf->type & 0x10)) printf("\tread-only object\n"); if (ino == root_inode) printf("\tactive root\n"); else if (inf->nparents < 1) printf("\torphan\n"); else if (inf->nparents > 1) printf("\tparent: #%x (%d)\n", inf->parent, inf->nparents); else if (pathstat < 0 || verbose2) printf("\tparent: #%x\n", inf->parent); if (verbose2 > 1) { if (inf->descend) sprintf(descend_str, "#%x", inf->descend); else strcpy(descend_str, "null"); if (inf->sibling) sprintf(sibling_str, "#%x", inf->sibling); else strcpy(sibling_str, "null"); printf("\tchild: %s, sibling: %s\n", descend_str, sibling_str); } if (!inf->len) printf("\treclaimed\n"); last_ino = ino; } exit(0); } void lsino_one(ino, assume_file) { struct inode_info *inf; char pathname[PATHNAME_BUF_SIZE], *type; if (!validate_inode(ino)) { fprintf(stderr, "lsino: specified inode number is invalid\n"); exit(1); } printf("inode #%x\n", ino); inf = inode_info[ino]; if (pathname_of_inode(ino, pathname) >= 0) printf("Pathname: %s\n", pathname); else printf("No pathname found\n"); inf = inode_info[ino]; switch (inf->type) { case 0x00: type = "deleted"; break; case 0xE1: type = "read-only file"; break; case 0xF1: type = "file"; break; case 0xF2: type = "directory"; break; case 0xF3: type = "symlink"; break; case 0xF4: type = "segment"; break; default: type = "???"; } printf("object type %02X (%s)\n", inf->type, type); if (!inf->len) { printf("This inode has been reclaimed\n\n"); return; } if (validate_obj_name(ino, 1)) printf("object name: %s\n", inf->dataptr); else { printf("No valid object name in the chunk\n\n"); return; } if (inf->type == 0xF1 || inf->type == 0xE1 || !inf->type && assume_file) { printf("total size: %lu bytes\n", (u_long) get_file_size(ino, !inf->type)); if (verbose2) ls_seg_file(ino, !inf->type); } putchar('\n'); } cmd_lsino(argc, argv) char **argv; { extern int optind; int c, assume_file = 0, ino; read_ffs_image(); find_inode_block(); alloc_inode_table(); find_root_inode(); treewalk_all(); optind = 0; while ((c = getopt(argc, argv, "fv")) != EOF) switch (c) { case 'f': assume_file++; continue; case 'v': verbose2++; continue; default: fprintf(stderr, "usage: lsino [-v[v]] [ino...]\n"); exit(1); } if (optind >= argc) return lsino_all(); for (; optind < argc; optind++) { ino = strtoul(argv[optind], 0, 16); lsino_one(ino, assume_file); } exit(0); }