Add c-flag to tail(1) and refactor manpage

and mark it as finished in README.
This commit is contained in:
FRIGN 2015-02-09 18:38:41 +01:00
parent 989127e525
commit 006c9739b3
3 changed files with 56 additions and 27 deletions

2
README
View File

@ -64,7 +64,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
=* sponge non-posix none
strings no -a, -n, -t
=* sync non-posix none
= tail no -c
=* tail yes none
=* tar non-posix none
=* tee yes none
test yes none

25
tail.1
View File

@ -7,7 +7,7 @@
.Sh SYNOPSIS
.Nm
.Op Fl f
.Op Fl n Ar num
.Op Fl c Ar num | Fl n Ar num
.Op Ar file ...
.Sh DESCRIPTION
.Nm
@ -20,19 +20,28 @@ is given,
reads from stdin.
.Sh OPTIONS
.Bl -tag -width Ds
.It Fl c Ar num | Fl n Ar num
Display
.Ar num
last characters | lines. If
.Ar num
begins with '+' it is used as an offset from the beginning of each
.Ar file .
If
.Ar num
begins with '-' it is handled the same as if no sign was given.
.It Fl f
If one
.Ar file
is specified, append lines to output as
.Ar file
grows.
.It Fl n Ar lines
Display
.Ar num
lines. If
.Ar num
begins with '+' it is used as an offset from the beginning of each
.Ar file .
.El
.Sh SEE ALSO
.Xr head 1
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification.

44
tail.c
View File

@ -9,43 +9,61 @@
#include <unistd.h>
#include "text.h"
#include "utf.h"
#include "util.h"
static int fflag = 0;
static void
dropinit(FILE *fp, const char *str, size_t n)
dropinit(FILE *fp, const char *str, size_t n, char mode)
{
Rune r;
char *buf = NULL;
size_t size = 0, i = 0;
ssize_t len;
if (mode == 'n') {
while (i < n && (len = getline(&buf, &size, fp)) != -1)
if (len > 0 && buf[len - 1] == '\n')
i++;
} else {
while (i < n && (len = readrune(str, fp, &r)))
i++;
}
free(buf);
concat(fp, str, stdout, "<stdout>");
}
static void
taketail(FILE *fp, const char *str, size_t n)
taketail(FILE *fp, const char *str, size_t n, char mode)
{
Rune *r = NULL;
char **ring = NULL;
size_t i, j, *size = NULL;
if (mode == 'n') {
ring = ecalloc(n, sizeof *ring);
size = ecalloc(n, sizeof *size);
for (i = j = 0; getline(&ring[i], &size[i], fp) != -1; )
i = j = (i + 1) % n;
} else {
r = ecalloc(n, sizeof *r);
for (i = j = 0; readrune(str, fp, &r[i]); )
i = j = (i + 1) % n;
}
if (ferror(fp))
eprintf("%s: read error:", str);
do {
if (ring[j]) {
if (ring && ring[j]) {
fputs(ring[j], stdout);
free(ring[j]);
}
if (r) {
writerune("<stdout>", stdout, &r[j]);
}
} while ((j = (j + 1) % n) != i);
free(ring);
@ -63,30 +81,32 @@ main(int argc, char *argv[])
{
struct stat st1, st2;
FILE *fp;
size_t n = 10, tmpsize;
size_t num = 10, tmpsize;
int ret = 0, newline, many;
char *lines, *tmp;
void (*tail)(FILE *, const char *, size_t) = taketail;
char mode = 'n', *numstr, *tmp;
void (*tail)(FILE *, const char *, size_t, char) = taketail;
ARGBEGIN {
case 'f':
fflag = 1;
break;
case 'c':
case 'n':
lines = EARGF(usage());
n = MIN(llabs(estrtonum(lines, LLONG_MIN + 1, MIN(LLONG_MAX, SIZE_MAX))), SIZE_MAX);
if (strchr(lines, '+'))
mode = ARGC();
numstr = EARGF(usage());
num = MIN(llabs(estrtonum(numstr, LLONG_MIN + 1, MIN(LLONG_MAX, SIZE_MAX))), SIZE_MAX);
if (strchr(numstr, '+'))
tail = dropinit;
break;
ARGNUM:
n = ARGNUMF();
num = ARGNUMF();
break;
default:
usage();
} ARGEND;
if (argc == 0)
tail(stdin, "<stdin>", n);
tail(stdin, "<stdin>", num, mode);
else {
if ((many = argc > 1) && fflag)
usage();
@ -104,7 +124,7 @@ main(int argc, char *argv[])
if (!(S_ISFIFO(st1.st_mode) || S_ISREG(st1.st_mode)))
fflag = 0;
newline = 1;
tail(fp, argv[0], n);
tail(fp, argv[0], num, mode);
if (fflag && argc == 1) {
tmp = NULL;