From c2496ab0e87c96d8f13357472b8ba4ea029fb524 Mon Sep 17 00:00:00 2001 From: DTB Date: Mon, 1 Jan 2024 21:59:37 -0700 Subject: [PATCH] 2024-01-01 work --- Wip/dj/dj.c | 84 +++++++++++++++++++++++++++++++---------------------- 1 file changed, 50 insertions(+), 34 deletions(-) diff --git a/Wip/dj/dj.c b/Wip/dj/dj.c index 1738fa4..a307b4b 100644 --- a/Wip/dj/dj.c +++ b/Wip/dj/dj.c @@ -2,9 +2,10 @@ #include /* open(2) */ #include /* fprintf(3), stderr */ #include /* free(3), malloc(3), strtol(3), size_t */ +#include /* memset(3) */ #include /* EX_OK, EX_USAGE */ -#include /* close(2), getopt(3), optarg, optind, STDIN_FILENO, - STDOUT_FILENO */ +#include /* close(2), getopt(3), read(2), write(2), optarg, optind, + STDIN_FILENO, STDOUT_FILENO */ #define ARGV0 (argv[0] == NULL ? "" : argv[0]) @@ -61,10 +62,10 @@ terminate(struct Io io[2]){ static int usage(char *argv0){ - fprintf(stderr, "Usage: %s (-f) (-c [count]\n" - "\t(-i [input file]) (-a) (-b [input block size])" + fprintf(stderr, "Usage: %s (-af) (-c [count]\n" + "\t(-i [input file]) (-b [input block size])" " (-s [input offset])\n" - "\t(-o [output file]) (-A) (-B [output block size])" + "\t(-o [output file]) (-B [output block size])" " (-S [output offset])\n", ARGV0); return EX_USAGE; } @@ -75,7 +76,6 @@ static char stdout_name = ""; int main(int argc, char *argv[]){ struct Io{ size_t index; - char align; char *fn; int rec; int prec; @@ -85,6 +85,7 @@ int main(int argc, char *argv[]){ size_t bufuse; char *buf; } io[2]; /* { read, write } same as pipe(2) */ + char align; int c; int count; size_t i; @@ -92,10 +93,11 @@ int main(int argc, char *argv[]){ char noerror; /* defaults */ + align = 0; count = 0; noerror = 0; - io[0].align = io[1].align = 0; io[0].bs = io[1].bs = 1024; + io[0].buf = io[1].buf = NULL; io[0].fd = STDIN_FILENO; io[0].fn = stdin_name; io[1].fd = STDOUT_FILENO; @@ -105,7 +107,7 @@ int main(int argc, char *argv[]){ io[0].seek = io[1].seek = 0; if(argc > 0) - while((c = getopt(argc, argv, "aAc:i:b:fs:o:B:S:")) != -1) + while((c = getopt(argc, argv, "ac:i:b:fs:o:B:S:")) != -1) if(c == 'i' || c == 'o'){ /* file arguments */ int t; @@ -118,23 +120,26 @@ int main(int argc, char *argv[]){ || (io[p].fd != STDIN_FILENO && io[p].fd != STDOUT_FILENO && fclose(io[p].f) == EOF){ + terminate(io); return oserr(argv[0], optarg); }else{ io[p].fd = t; io[p].fn = optarg; } + /* boolean arguments */ + }else if(c == 'a') + align = 1; + else if(c == 'f') + noerror = 1; /* numeric arguments */ - }else if(!((c == 'c' && (count = parse(optarg)) < 0) + else if(!((c == 'c' && (count = parse(optarg)) < 0) || (c == 'b' && (io[0].bs = parse(optarg)) < 0) || (c == 's' && (io[0].seek = parse(optarg)) < 0) || (c == 'B' && (io[1].bs = parse(optarg)) < 0) - || (c == 'S' && (io[1].seek = parse(optarg)) < 0))) + || (c == 'S' && (io[1].seek = parse(optarg)) < 0))){ + terminate(io); return usage(argv[0]); - /* boolean arguments */ - else if(c == 'a' || c == 'A') - io[c == 'A'].align = 1; - else if(c == 'f') - noerror = 1; + } if(argc > optind) return usage(argv[0]); @@ -144,20 +149,37 @@ int main(int argc, char *argv[]){ if((io[p].buf = malloc(io[p].bs * (sizeof io[p].buf))) == NULL){ fprintf(stderr, "%s: Failed to allocate %d bytes\n", ARGV0, io[p].bs); + terminate(io); return EX_OSERR; }else if(io[p].seek > 0){ /* seek */ - if(io[p].fd == STDIN_FILENO){ - do{ io[p].seek -= (io[p].bufuse - = _read(io[p].fd, io[p].buf, - io[p].bs < io[p].seek ? io[p].bs : io[p].seek)); - if(io[p].bufuse == 0) - return terminate(output(io)); - }while(io[p].seek > 0); - else if(io[p].f == stdout) - for(i = 0; i < io[p].seek; ++i) - putc('\0', io[p].f; - else if(fseek(io[p].f, io[p].seek, SEEK_SET) == -1) - return oserr(argv[0], io[p].fn); + if(io[p].fd == STDIN_FILENO + || io[p].fd == STDOUT_FILENO + || lseek(io[p].fd, io[p].seek, SEEK_SET) == -1){ + if(p == 0){ + do if((io[p].bufuse = _read(io[p].fd, io[p].buf, + io[p].bs < io[p].seek + ? io[p].bs + : io[p].seek)) + != 0) + io[p].seek -= io[p].bufuse; + else /* not enough to skip */ + return terminate(output(io)); + while(io[p].seek > 0); + }else{ + memset(io[p].buf, '\0', io[p].bs); + /* cheat and use bufuse as the retval for write + * (the buffer is zeroed, it doesn't matter) */ + do if((io[p].bufuse = write(io[p].fd, io[p].buf, + io[p].bs < io[p].seek + ? io[p].bs + : io[p].seek)) + != 0) + io[p].seek -= io[p].bufuse; + else + return terminate(output(io)); + while(io[p].seek > 0); + } + } } } @@ -175,11 +197,5 @@ int main(int argc, char *argv[]){ }while(count == 0 || --count > 0); - for(i = 0; i <= 1; ++i){ - free(io[i].buf); - if(io[i].fd != STDIN_FILENO && io[i].fd != STDOUT_FILENO) - close(io[i].fd); - } - - return EX_OK; + return terminate(output(io)); }