1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1992-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * * 20 ***********************************************************************/ 21 #pragma prototyped 22 /* 23 * rev [-l] [file ...] 24 * 25 * reverse the characters or lines of one or more files 26 * 27 * David Korn 28 * AT&T Laboratories 29 * dgk@research.att.com 30 * 31 */ 32 33 static const char usage[] = 34 "[-?\n@(#)$Id: rev (AT&T Research) 1999-04-10 $\n]" 35 USAGE_LICENSE 36 "[+NAME?rev - reverse the characters or lines of one or more files]" 37 "[+DESCRIPTION?\brev\b copies one or more files to standard output " 38 "reversing the order of characters on every line of the file " 39 "or reversing the order of lines of the file if \b-l\b is specified.]" 40 "[+?If no \afile\a is given, or if the \afile\a is \b-\b, \brev\b " 41 "copies from standard input starting at the current offset.]" 42 "[l:line?Reverse the lines of the file.]" 43 44 "\n" 45 "\n[file ...]\n" 46 "\n" 47 "[+EXIT STATUS?]{" 48 "[+0?All files copied successfully.]" 49 "[+>0?One or more files did not copy.]" 50 "}" 51 "[+SEE ALSO?\bcat\b(1), \btail\b(1)]" 52 ; 53 54 #include <cmd.h> 55 #include <rev.h> 56 57 /* 58 * reverse the characters within a line 59 */ 60 static int rev_char(Sfio_t *in, Sfio_t *out) 61 { 62 register int c; 63 register char *ep, *bp, *cp; 64 register int n; 65 while(cp = bp = sfgetr(in,'\n',0)) 66 { 67 ep = bp + (n=sfvalue(in)) -1; 68 while(ep > bp) 69 { 70 c = *--ep; 71 *ep = *bp; 72 *bp++ = c; 73 } 74 if(sfwrite(out,cp,n)<0) 75 return(-1); 76 } 77 return(0); 78 } 79 80 int 81 b_rev(int argc, register char** argv, void* context) 82 { 83 register Sfio_t *fp; 84 register char *cp; 85 register int n, line=0; 86 NOT_USED(argc); 87 88 cmdinit(argc, argv, context, ERROR_CATALOG, 0); 89 while (n = optget(argv, usage)) switch (n) 90 { 91 case 'l': 92 line=1; 93 break; 94 case ':': 95 error(2, "%s", opt_info.arg); 96 break; 97 case '?': 98 error(ERROR_usage(2), "%s", opt_info.arg); 99 break; 100 } 101 argv += opt_info.index; 102 if(error_info.errors) 103 error(ERROR_usage(2),"%s",optusage((char*)0)); 104 n=0; 105 if(cp = *argv) 106 argv++; 107 do 108 { 109 if(!cp || streq(cp,"-")) 110 fp = sfstdin; 111 else if(!(fp = sfopen((Sfio_t*)0,cp,"r"))) 112 { 113 error(ERROR_system(0),"%s: cannot open",cp); 114 n=1; 115 continue; 116 } 117 if(line) 118 line = rev_line(fp,sfstdout,sftell(fp)); 119 else 120 line = rev_char(fp,sfstdout); 121 if(fp!=sfstdin) 122 sfclose(fp); 123 if(line < 0) 124 error(ERROR_system(1),"write failed"); 125 } 126 while(cp= *argv++); 127 return(n); 128 } 129