Mercurial > hg > toybox
view toys/posix/df.c @ 1531:3ff823086c99 draft
Teach ln -f to leave original target alone if link creation fails.
Suggested by Ashwini Sharma, I wound up implementing it by creating the new
link at a temporary name and renaming it over the old one instead of renaming
the old file out of the way and putting it back if it failed.
(Because "mkdir -p one/one/blah && ln -sf /bin/one one" would otherwise
rename one/one out of the way and only notice it can't delete it way at the
end when recovery's darn awkward, vs create new thing and if rename fails
(including EISDIR) that's the main error path. And yes the temporary name
is in the same directory as the destination so we never rename between mounts.)
link over the old one instead of renaming the old file and renaming it back.
author | Rob Landley <rob@landley.net> |
---|---|
date | Wed, 22 Oct 2014 17:11:06 -0500 |
parents | 4d898affda0c |
children | 991f4d613388 |
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/* df.c - report free disk space. * * Copyright 2006 Rob Landley <rob@landley.net> * * See http://opengroup.org/onlinepubs/9699919799/utilities/df.html USE_DF(NEWTOY(df, "Pkt*a", TOYFLAG_USR|TOYFLAG_SBIN)) config DF bool "df" default y help usage: df [-t type] [FILESYSTEM ...] The "disk free" command shows total/used/available disk space for each filesystem listed on the command line, or all currently mounted filesystems. -t type Display only filesystems of this type. config DF_PEDANTIC bool "options -P and -k" default y depends on DF help usage: df [-Pk] -P The SUSv3 "Pedantic" option -k Sets units back to 1024 bytes (the default without -P) Pedantic provides a slightly less useful output format dictated by Posix, and sets the units to 512 bytes instead of the default 1024 bytes. */ #define FOR_df #include "toys.h" GLOBALS( struct arg_list *fstype; long units; ) static void show_mt(struct mtab_list *mt) { int len; long long size, used, avail, percent, block; char *device; // Return if it wasn't found (should never happen, but with /etc/mtab...) if (!mt) return; // If we have -t, skip other filesystem types if (TT.fstype) { struct arg_list *al; for (al = TT.fstype; al; al = al->next) if (!strcmp(mt->type, al->arg)) break; if (!al) return; } // If we don't have -a, skip synthetic filesystems if (!(toys.optflags & FLAG_a) && !mt->statvfs.f_blocks) return; // Figure out how much total/used/free space this filesystem has, // forcing 64-bit math because filesystems are big now. block = mt->statvfs.f_bsize ? mt->statvfs.f_bsize : 1; size = (block * mt->statvfs.f_blocks) / TT.units; used = (block * (mt->statvfs.f_blocks-mt->statvfs.f_bfree)) / TT.units; avail = (block * (getuid() ? mt->statvfs.f_bavail : mt->statvfs.f_bfree)) / TT.units; if (!(used+avail)) percent = 0; else { percent = (used*100)/(used+avail); if (used*100 != percent*(used+avail)) percent++; } device = *mt->device == '/' ? realpath(mt->device, NULL) : NULL; if (!device) device = mt->device; // Figure out appropriate spacing len = 25 - strlen(device); if (len < 1) len = 1; if (CFG_DF_PEDANTIC && (toys.optflags & FLAG_P)) { xprintf("%s %lld %lld %lld %lld%% %s\n", device, size, used, avail, percent, mt->dir); } else { xprintf("%s% *lld % 10lld % 9lld % 3lld%% %s\n", device, len, size, used, avail, percent, mt->dir); } if (device != mt->device) free(device); } void df_main(void) { struct mtab_list *mt, *mtstart, *mtend; // Handle -P and -k TT.units = 1024; if (CFG_DF_PEDANTIC && (toys.optflags & FLAG_P)) { // Units are 512 bytes if you select "pedantic" without "kilobytes". if ((toys.optflags&(FLAG_P|FLAG_k)) == FLAG_P) TT.units = 512; printf("Filesystem %ld-blocks Used Available Capacity Mounted on\n", TT.units); } else puts("Filesystem\t1K-blocks\tUsed Available Use% Mounted on"); if (!(mtstart = xgetmountlist(0))) return; mtend = dlist_terminate(mtstart); // If we have a list of filesystems on the command line, loop through them. if (*toys.optargs) { char **next; for(next = toys.optargs; *next; next++) { struct stat st; // Stat it (complain if we can't). if(stat(*next, &st)) { perror_msg("`%s'", *next); continue; } // Find and display this filesystem. Use _last_ hit in case of // overmounts (which is first hit in the reversed list). for (mt = mtend; mt; mt = mt->prev) { if (st.st_dev == mt->stat.st_dev) { show_mt(mt); break; } } } } else { // Loop through mount list to filter out overmounts. for (mt = mtend; mt; mt = mt->prev) { struct mtab_list *mt2, *mt3; // 0:0 is LANANA null device if (!mt->stat.st_dev) continue; // Filter out overmounts. mt3 = mt; for (mt2 = mt->prev; mt2; mt2 = mt2->prev) { if (mt->stat.st_dev == mt2->stat.st_dev) { // For --bind mounts, take show earliest mount if (!strcmp(mt->device, mt2->device)) { if (!toys.optflags & FLAG_a) mt3->stat.st_dev = 0; mt3 = mt2; } else mt2->stat.st_dev = 0; } } } // Cosmetic: show filesystems in creation order for (mt = mtstart; mt; mt = mt->next) if (mt->stat.st_dev) show_mt(mt); } if (CFG_TOYBOX_FREE) llist_traverse(mtstart, free); }