Mercurial > hg > toybox
view toys/posix/nl.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 | 63db77909fc8 |
children |
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/* nl.c - print line numbers * * Copyright 2013 CE Strake <strake888@gmail.com> * * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/nl.html * * This implements a subset: only one logical page (-ip), no sections (-dfh). * todo: -lv USE_NL(NEWTOY(nl, "v#<1=1l#b:n:s:w#<0=6E", TOYFLAG_BIN)) config NL bool "nl" default y help usage: nl [-E] [-l #] [-b MODE] [-n STYLE] [-s SEPARATOR] [-w WIDTH] [FILE...] Number lines of input. -E Use extended regex syntax (when doing -b pREGEX) -b which lines to number: a (all) t (non-empty, default) pREGEX (pattern) -l Only count last of this many consecutive blank lines -n number STYLE: ln (left justified) rn (right justified) rz (zero pad) -s Separator to use between number and line (instead of TAB) -w Width of line numbers (default 6) */ #define FOR_nl #include "toys.h" GLOBALS( long w; char *s; char *n; char *b; long l; long v; // Count of consecutive blank lines for -l has to persist between files long lcount; ) void do_nl(int fd, char *name) { FILE *f = xfdopen(fd, "r"); int w = TT.w, slen = strlen(TT.s); for (;;) { char *line = 0; size_t temp; int match = *TT.b != 'n'; if (getline(&line, &temp, f) < 1) { if (ferror(f)) perror_msg("%s", name); break; } if (*TT.b == 'p') match = !regexec((void *)(toybuf+16), line, 0, 0, 0); if (TT.l || *TT.b == 't') if (*line == '\n') match = TT.l && ++TT.lcount >= TT.l; if (match) { TT.lcount = 0; printf(toybuf, w, TT.v++, TT.s); } else printf("%*c", (int)w+slen, ' '); xprintf("%s", line); free(line); } fclose(f); } void nl_main(void) { char *clip = ""; if (!TT.s) TT.s = "\t"; if (!TT.n || !strcmp(TT.n, "rn")); // default else if (!strcmp(TT.n, "ln")) clip = "-"; else if (!strcmp(TT.n, "rz")) clip = "0"; else error_exit("bad -n '%s'", TT.n); sprintf(toybuf, "%%%s%s", clip, "*ld%s"); if (!TT.b) TT.b = "t"; if (*TT.b == 'p' && TT.b[1]) xregcomp((void *)(toybuf+16), TT.b+1, REG_NOSUB | (toys.optflags&FLAG_E)*REG_EXTENDED); else if (!strchr("atn", *TT.b)) error_exit("bad -b '%s'", TT.b); loopfiles (toys.optargs, do_nl); }