sbase

suckless unix tools
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commit 3276fbea1cfb23ed5eeb11aa18813c461acca004
parent 9a3b12525bd3a2627f5a45c7afe00737a041bb5b
Author: Michael Forney <mforney@mforney.org>
Date:   Mon,  3 Jul 2017 14:58:49 -0700

concat: Use plain read/write instead of buffered stdio

If we are just copying data from one file to another, we don't need to
fill a complete buffer, just read a chunk at a time, and write it to the
output.

Diffstat:
cat.c | 39+++++++++++++++------------------------
libutil/concat.c | 24++++++++++++++----------
libutil/cp.c | 49++++++++++++++++++++-----------------------------
sponge.c | 31+++++++++++++++++--------------
tail.c | 199++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------
text.h | 1-
util.h | 1+
xinstall.c | 25++++++++++++-------------
8 files changed, 200 insertions(+), 169 deletions(-)

diff --git a/cat.c b/cat.c @@ -1,22 +1,11 @@ /* See LICENSE file for copyright and license details. */ -#include <stdio.h> +#include <fcntl.h> #include <string.h> #include <unistd.h> -#include "text.h" #include "util.h" static void -uconcat(FILE *fp1, const char *s1, FILE *fp2, const char *s2) -{ - int c; - - setbuf(fp2, NULL); - while ((c = getc(fp1)) != EOF) - putc(c, fp2); -} - -static void usage(void) { eprintf("usage: %s [-u] [file ...]\n", argv0); @@ -25,37 +14,39 @@ usage(void) int main(int argc, char *argv[]) { - FILE *fp; - int ret = 0; - void (*cat)(FILE *, const char *, FILE *, const char *) = &concat; + int fd, ret = 0; ARGBEGIN { case 'u': - cat = &uconcat; break; default: usage(); } ARGEND if (!argc) { - cat(stdin, "<stdin>", stdout, "<stdout>"); + if (concat(0, "<stdin>", 1, "<stdout>") < 0) + ret = 1; } else { for (; *argv; argc--, argv++) { if (!strcmp(*argv, "-")) { *argv = "<stdin>"; - fp = stdin; - } else if (!(fp = fopen(*argv, "r"))) { - weprintf("fopen %s:", *argv); + fd = 0; + } else if ((fd = open(*argv, O_RDONLY)) < 0) { + weprintf("open %s:", *argv); ret = 1; continue; } - cat(fp, *argv, stdout, "<stdout>"); - if (fp != stdin && fshut(fp, *argv)) + switch (concat(fd, *argv, 1, "<stdout>")) { + case -1: ret = 1; + break; + case -2: + return 1; /* exit on write error */ + } + if (fd != 0) + close(fd); } } - ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>"); - return ret; } diff --git a/libutil/concat.c b/libutil/concat.c @@ -1,19 +1,23 @@ /* See LICENSE file for copyright and license details. */ -#include <stdio.h> +#include <unistd.h> -#include "../text.h" #include "../util.h" -void -concat(FILE *fp1, const char *s1, FILE *fp2, const char *s2) +int +concat(int f1, const char *s1, int f2, const char *s2) { char buf[BUFSIZ]; - size_t n; + ssize_t n; - while ((n = fread(buf, 1, sizeof(buf), fp1))) { - fwrite(buf, 1, n, fp2); - - if (feof(fp1) || ferror(fp1) || ferror(fp2)) - break; + while ((n = read(f1, buf, sizeof(buf))) > 0) { + if (writeall(f2, buf, n) < 0) { + weprintf("write %s:", s2); + return -2; + } + } + if (n < 0) { + weprintf("read %s:", s1); + return -1; } + return 0; } diff --git a/libutil/cp.c b/libutil/cp.c @@ -12,7 +12,6 @@ #include <utime.h> #include "../fs.h" -#include "../text.h" #include "../util.h" int cp_aflag = 0; @@ -27,7 +26,7 @@ int cp(const char *s1, const char *s2, int depth) { DIR *dp; - FILE *f1, *f2; + int f1, f2; struct dirent *d; struct stat st; struct timespec times[2]; @@ -113,46 +112,38 @@ cp(const char *s1, const char *s2, int depth) return 0; } } else { - if (!(f1 = fopen(s1, "r"))) { - weprintf("fopen %s:", s1); + if ((f1 = open(s1, O_RDONLY)) < 0) { + weprintf("open %s:", s1); cp_status = 1; return 0; } - if (!(f2 = fopen(s2, "w"))) { - if (cp_fflag) { - if (unlink(s2) < 0 && errno != ENOENT) { - weprintf("unlink %s:", s2); - cp_status = 1; - fclose(f1); - return 0; - } else if (!(f2 = fopen(s2, "w"))) { - weprintf("fopen %s:", s2); - cp_status = 1; - fclose(f1); - return 0; - } - } else { - weprintf("fopen %s:", s2); + if ((f2 = creat(s2, st.st_mode)) < 0 && cp_fflag) { + if (unlink(s2) < 0 && errno != ENOENT) { + weprintf("unlink %s:", s2); cp_status = 1; - fclose(f1); + close(f1); return 0; } + f2 = creat(s2, st.st_mode); } - concat(f1, s1, f2, s2); - - /* preserve permissions by default */ - fchmod(fileno(f2), st.st_mode); - - if (fclose(f2) == EOF) { - weprintf("fclose %s:", s2); + if (f2 < 0) { + weprintf("creat %s:", s2); cp_status = 1; + close(f1); return 0; } - if (fclose(f1) == EOF) { - weprintf("fclose %s:", s1); + if (concat(f1, s1, f2, s2) < 0) { cp_status = 1; + close(f1); + close(f2); return 0; } + + /* preserve permissions by default */ + fchmod(f2, st.st_mode); + + close(f1); + close(f2); } if (cp_aflag || cp_pflag) { diff --git a/sponge.c b/sponge.c @@ -1,7 +1,8 @@ /* See LICENSE file for copyright and license details. */ -#include <stdio.h> +#include <fcntl.h> +#include <stdlib.h> +#include <unistd.h> -#include "text.h" #include "util.h" static void @@ -13,24 +14,26 @@ usage(void) int main(int argc, char *argv[]) { - FILE *fp, *tmpfp; - int ret = 0; + char tmp[] = "/tmp/sponge-XXXXXX"; + int fd, tmpfd; argv0 = argv[0], argc--, argv++; if (argc != 1) usage(); - if (!(tmpfp = tmpfile())) - eprintf("tmpfile:"); - concat(stdin, "<stdin>", tmpfp, "<tmpfile>"); - rewind(tmpfp); + if ((tmpfd = mkstemp(tmp)) < 0) + eprintf("mkstemp:"); + unlink(tmp); + if (concat(0, "<stdin>", tmpfd, "<tmpfile>") < 0) + return 1; + if (lseek(tmpfd, 0, SEEK_SET) < 0) + eprintf("lseek:"); - if (!(fp = fopen(argv[0], "w"))) - eprintf("fopen %s:", argv[0]); - concat(tmpfp, "<tmpfile>", fp, argv[0]); + if ((fd = creat(argv[0], 0666)) < 0) + eprintf("creat %s:", argv[0]); + if (concat(tmpfd, "<tmpfile>", fd, argv[0]) < 0) + return 1; - ret |= fshut(fp, argv[0]) | fshut(tmpfp, "<tmpfile>"); - - return ret; + return 0; } diff --git a/tail.c b/tail.c @@ -1,80 +1,125 @@ /* See LICENSE file for copyright and license details. */ #include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> -#include "text.h" #include "utf.h" #include "util.h" static char mode = 'n'; -static void -dropinit(FILE *fp, const char *str, size_t n) +static int +dropinit(int fd, const char *fname, size_t count) { Rune r; - char *buf = NULL; - size_t size = 0, i = 1; - ssize_t len; + char buf[BUFSIZ], *p; + ssize_t n; + int nr; + + if (count < 2) + goto copy; + count--; /* numbering starts at 1 */ + while (count && (n = read(fd, buf, sizeof(buf))) > 0) { + if (mode == 'n') { + for (p = buf; count && n > 0; p++, n--) { + if (*p == '\n') + count--; + } + } else { + for (p = buf; count && n > 0; p += nr, n -= nr, count--) { + nr = charntorune(&r, p, n); + if (!nr) { + /* we don't have a full rune, move + * remaining data to beginning and read + * again */ + memmove(buf, p, n); + break; + } + } + } + } + if (count) { + if (n < 0) + weprintf("read %s:", fname); + if (n <= 0) + return n; + } - if (mode == 'n') { - while (i < n && (len = getline(&buf, &size, fp)) > 0) - if (len > 0 && buf[len - 1] == '\n') - i++; - } else { - while (i < n && efgetrune(&r, fp, str)) - i++; + /* write the rest of the buffer */ + if (writeall(1, p, n) < 0) + eprintf("write:"); +copy: + switch (concat(fd, fname, 1, "<stdout>")) { + case -1: /* read error */ + return -1; + case -2: /* write error */ + exit(1); + default: + return 0; } - free(buf); - concat(fp, str, stdout, "<stdout>"); } -static void -taketail(FILE *fp, const char *str, size_t n) +static int +taketail(int fd, const char *fname, size_t count) { - Rune *r = NULL; - struct line *ring = NULL; - size_t i, j, *size = NULL; - ssize_t len; - int seenln = 0; - - if (!n) - return; - - if (mode == 'n') { - ring = ecalloc(n, sizeof(*ring)); - size = ecalloc(n, sizeof(*size)); - - for (i = j = 0; (len = getline(&ring[i].data, - &size[i], fp)) > 0; seenln = 1) { - ring[i].len = len; - i = j = (i + 1) % n; + static char *buf = NULL; + static size_t size = 0; + char *p; + size_t len = 0, left; + ssize_t n; + + if (!count) + return 0; + for (;;) { + if (len + BUFSIZ > size) { + /* make sure we have at least BUFSIZ to read */ + size += 2 * BUFSIZ; + buf = erealloc(buf, size); } - } else { - r = ecalloc(n, sizeof(*r)); - - for (i = j = 0; efgetrune(&r[i], fp, str); ) - i = j = (i + 1) % n; - } - if (ferror(fp)) - eprintf("%s: read error:", str); - - do { - if (seenln && ring && ring[j].data) { - fwrite(ring[j].data, 1, ring[j].len, stdout); - free(ring[j].data); - } else if (r) { - efputrune(&r[j], stdout, "<stdout>"); + n = read(fd, buf + len, size - len); + if (n < 0) { + weprintf("read %s:", fname); + return -1; } - } while ((j = (j + 1) % n) != i); - - free(ring); - free(size); - free(r); + if (n == 0) + break; + len += n; + if (mode == 'n') { + /* ignore the last character; if it is a newline, it + * ends the last line */ + for (p = buf + len - 2, left = count; p >= buf; p--) { + if (*p != '\n') + continue; + left--; + if (!left) { + p++; + break; + } + } + } else { + for (p = buf + len - 1, left = count; p >= buf; p--) { + /* skip utf-8 continuation bytes */ + if ((*p & 0xc0) == 0x80) + continue; + left--; + if (!left) + break; + } + } + if (p > buf) { + len -= p - buf; + memmove(buf, p, len); + } + } + if (writeall(1, buf, len) < 0) + eprintf("write:"); + return 0; } static void @@ -87,11 +132,11 @@ int main(int argc, char *argv[]) { struct stat st1, st2; - FILE *fp; - size_t tmpsize, n = 10; + int fd; + size_t n = 10; int fflag = 0, ret = 0, newline = 0, many = 0; - char *numstr, *tmp; - void (*tail)(FILE *, const char *, size_t) = taketail; + char *numstr; + int (*tail)(int, const char *, size_t) = taketail; ARGBEGIN { case 'f': @@ -113,17 +158,18 @@ main(int argc, char *argv[]) usage(); } ARGEND - if (!argc) - tail(stdin, "<stdin>", n); - else { + if (!argc) { + if (tail(0, "<stdin>", n) < 0) + ret = 1; + } else { if ((many = argc > 1) && fflag) usage(); for (newline = 0; *argv; argc--, argv++) { if (!strcmp(*argv, "-")) { *argv = "<stdin>"; - fp = stdin; - } else if (!(fp = fopen(*argv, "r"))) { - weprintf("fopen %s:", *argv); + fd = 0; + } else if ((fd = open(*argv, O_RDONLY)) < 0) { + weprintf("open %s:", *argv); ret = 1; continue; } @@ -134,27 +180,26 @@ main(int argc, char *argv[]) if (!(S_ISFIFO(st1.st_mode) || S_ISREG(st1.st_mode))) fflag = 0; newline = 1; - tail(fp, *argv, n); + if (tail(fd, *argv, n) < 0) { + ret = 1; + fflag = 0; + } if (!fflag) { - if (fp != stdin && fshut(fp, *argv)) - ret = 1; + if (fd != 0) + close(fd); continue; } - for (tmp = NULL, tmpsize = 0;;) { - while (getline(&tmp, &tmpsize, fp) > 0) { - fputs(tmp, stdout); - fflush(stdout); - } - if (ferror(fp)) - eprintf("readline %s:", *argv); - clearerr(fp); + for (;;) { + if (concat(fd, *argv, 1, "<stdout>") < 0) + exit(1); /* ignore error in case file was removed, we continue * tracking the existing open file descriptor */ if (!stat(*argv, &st2)) { if (st2.st_size < st1.st_size) { fprintf(stderr, "%s: file truncated\n", *argv); - rewind(fp); + if (lseek(fd, SEEK_SET, 0) < 0) + eprintf("lseek:"); } st1 = st2; } @@ -163,7 +208,5 @@ main(int argc, char *argv[]) } } - ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>"); - return ret; } diff --git a/text.h b/text.h @@ -13,5 +13,4 @@ struct linebuf { #define EMPTY_LINEBUF {NULL, 0, 0,} void getlines(FILE *, struct linebuf *); -void concat(FILE *, const char *, FILE *, const char *); int linecmp(struct line *, struct line *); diff --git a/util.h b/util.h @@ -64,6 +64,7 @@ int eregcomp(regex_t *, const char *, int); /* io */ ssize_t writeall(int, const void *, size_t); +int concat(int, const char *, int, const char *); /* misc */ void enmasse(int, char **, int (*)(const char *, const char *, int)); diff --git a/xinstall.c b/xinstall.c @@ -2,6 +2,7 @@ #include <grp.h> #include <pwd.h> #include <errno.h> +#include <fcntl.h> #include <unistd.h> #include <stdlib.h> #include <string.h> @@ -10,7 +11,6 @@ #include <sys/wait.h> #include "util.h" -#include "text.h" static int Dflag = 0; static gid_t group; @@ -44,7 +44,7 @@ static int install(const char *s1, const char *s2, int depth) { DIR *dp; - FILE *f1, *f2; + int f1, f2; struct dirent *d; struct stat st; ssize_t r; @@ -92,23 +92,22 @@ install(const char *s1, const char *s2, int depth) else if (mknod(s2, (st.st_mode & ~07777) | mode, st.st_rdev) < 0) eprintf("mknod %s:", s2); } else { - if (!(f1 = fopen(s1, "r"))) - eprintf("fopen %s:", s1); - if (!(f2 = fopen(s2, "w"))) { + if ((f1 = open(s1, O_RDONLY)) < 0) + eprintf("open %s:", s1); + if ((f2 = creat(s2, 0600)) < 0) { if (unlink(s2) < 0 && errno != ENOENT) eprintf("unlink %s:", s2); - else if (!(f2 = fopen(s2, "w"))) - eprintf("fopen %s:", s2); + if ((f2 = creat(s2, 0600)) < 0) + eprintf("creat %s:", s2); } - concat(f1, s1, f2, s2); + if (concat(f1, s1, f2, s2) < 0) + exit(1); - if (fchmod(fileno(f2), mode) < 0) + if (fchmod(f2, mode) < 0) eprintf("fchmod %s:", s2); - if (fclose(f2) == EOF) - eprintf("fclose %s:", s2); - if (fclose(f1) == EOF) - eprintf("fclose %s:", s1); + close(f1); + close(f2); } if (lchown(s2, owner, group) < 0)