Minor cleanups and clarifications.
[oweals/busybox.git] / ar.c
diff --git a/ar.c b/ar.c
index 27dfadd1db62cb3a6bf426957c0e41297556d86f..5aba30de0fe5bffa017afaa13ab1d09bb12502e6 100644 (file)
--- a/ar.c
+++ b/ar.c
@@ -3,8 +3,8 @@
  * Mini ar implementation for busybox 
  *
  * Copyright (C) 2000 by Glenn McGrath
- * Written by Glenn McGrath <bug1@netconnect.com.au> 1 June 2000
- *
+ * Written by Glenn McGrath <bug1@optushome.com.au> 1 June 2000
+ *             
  * Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
  *
  * This program is free software; you can redistribute it and/or modify
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
- * Last modified 10 June 2000
  */
-
-
-#include <stdio.h>
 #include <fcntl.h>
-#include <errno.h>
-#include <ctype.h>
-#include <time.h>
-#include <utime.h>
-#include <sys/types.h>
-#include "internal.h"
-
-#define AR_BLOCK_SIZE 60
-#define AR_PRESERVE_DATE 1     /* preserve original dates */
-#define AR_VERBOSE       2     /* be verbose */
-#define AR_DISPLAY       4     /* display contents */
-#define AR_EXT_TO_FILE   8     /* extract contents of archive */
-#define AR_EXT_TO_STDOUT 16    /* extract to stdout */
-
-#define BB_DECLARE_EXTERN
-#define bb_need_io_error
-#include "messages.c"
-
-struct ArHeader {                              /* Byte Offset */
-       char ar_name[16];                       /*  0-15 */
-       char ar_date[12];                       /* 16-27 */
-       char ar_uid[6], ar_gid[6];      /* 28-39 */
-       char ar_mode[8];                        /* 40-47 */
-       char ar_size[10];                       /* 48-57 */
-       char ar_fmag[2];                        /* 58-59 */
-};
-typedef struct ArHeader ArHeader;
-
-struct ArInfo {
-       char name[17];                          /* File name */
-       time_t date;                            /* long int, No of seconds since epoch */
-       uid_t uid;                                      /* unsigned int, Numeric UID */
-       gid_t gid;                                      /* unsigned int, Numeric GID */
-       mode_t mode;                            /* unsigned int, Unix mode */
-       size_t size;                            /* int, Size of the file */
-};
-typedef struct ArInfo ArInfo;
-
-static const char ar_usage[] = "ar [optxvV] archive [filenames] \n"
-#ifndef BB_FEATURE_TRIVIAL_HELP
-       "\nExtract or list files from an ar archive.\n\n"
-       "Options:\n"
-       "\to\t\tpreserve original dates\n"
-       "\tp\t\textract to stdout\n"
-       "\tt\t\tlist\n"
-       "\tx\t\textract\n"
-       "\tv\t\tverbosely list files processed\n"
-#endif
-       ;
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <unistd.h>
+#include "busybox.h"
+
+typedef struct ar_headers_s {
+       char *name;
+       size_t size;
+       uid_t uid;
+       gid_t gid;
+       mode_t mode;
+       time_t mtime;
+       off_t offset;
+       struct ar_headers_s *next;
+} ar_headers_t;
 
 /*
- * Display details of a file, verbosly if funct=2   
+ * return the headerL_t struct for the filename descriptor
  */
-static void displayEntry(struct ArInfo *entry, int funct)
+extern ar_headers_t get_headers(int srcFd)
 {
-       /* TODO convert mode to string */
-       if ((funct & AR_VERBOSE) == AR_VERBOSE)
-               printf("%i %i/%i %8i %s ", entry->mode, entry->uid, entry->gid,
-                          entry->size, timeString(entry->date));
-       printf("%s\n", entry->name);
-}
-
-/* this is from tar.c remove later*/
-static long getOctal(const char *cp, int size)
-{
-        long val = 0;
-
-        for(;(size > 0) && (*cp == ' '); cp++, size--);
-        if ((size == 0) || !isOctal(*cp))
-                return -1;
-        for(; (size > 0) && isOctal(*cp); size--) {
-                val = val * 8 + *cp++ - '0';
-        }
-        for (;(size > 0) && (*cp == ' '); cp++, size--);
-        if ((size > 0) && *cp)
-                return -1;
-        return val;
-}
-
-/*
- * Converts from the char based struct to a new struct with stricter types
- */
-static int processArHeader(struct ArHeader *rawHeader, struct ArInfo *header)
-{
-       int count2;
-       int count;
+       typedef struct raw_ar_header_s {        /* Byte Offset */
+               char name[16];  /*  0-15 */
+               char date[12];  /* 16-27 */
+               char uid[6];    
+               char gid[6];    /* 28-39 */
+               char mode[8];   /* 40-47 */
+               char size[10];  /* 48-57 */
+               char fmag[2];   /* 58-59 */
+       } raw_ar_header_t;
+       raw_ar_header_t raw_ar_header;
+
+       ar_headers_t *head, *entry;
+       char ar_magic[8];
+       char *long_name=NULL;
        
-       /* check end of header marker is valid */
-       if ((rawHeader->ar_fmag[0]!='`') || (rawHeader->ar_fmag[1]!='\n')) 
-               return(FALSE); 
-
-       /* convert filename */ 
-       for (count = 0; count < 16; count++) {
-               /* allow spaces in filename except at the end */
-               if (rawHeader->ar_name[count] == ' ') {
-                       for (count2 = count; count2 < 16; count2++)
-                               if (!isspace(rawHeader->ar_name[count2]))
-                                       break;
-                       if (count2 >= 16)
+       head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+       entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+       
+       /* check ar magic */
+       if (full_read(srcFd, ar_magic, 8) != 8)
+               error_msg_and_die("cannot read magic");
+       if (strncmp(ar_magic,"!<arch>",7) != 0)
+               error_msg_and_die("invalid magic");
+
+       while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
+               /* check the end of header markers are valid */
+               if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
+                       char newline[1];
+                       if (raw_ar_header.fmag[1]!='`') {
                                break;
+                       }
+                       /* some version of ar, have an extra '\n' after each entry */
+                       read(srcFd, newline, 1);
+                       if (newline[0]!='\n') {
+                               break;
+                       }
+                       /* fix up the header, we started reading 1 byte too early due to a '\n' */
+                       memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
+                       /* dont worry about adding the last '\n', we dont need it now */
                }
-               /* GNU ar uses '/' as an end of filename marker */
-               if (rawHeader->ar_name[count] == '/')
-                       break;
-               header->name[count] = rawHeader->ar_name[count];
-       }
-       header->name[count] = '\0';
-       header->date = atoi(rawHeader->ar_date);
-       header->uid = atoi(rawHeader->ar_uid);
-       header->gid = atoi(rawHeader->ar_gid);
-       header->mode = getOctal(rawHeader->ar_mode, sizeof(rawHeader->ar_mode));
-       header->size = atoi(rawHeader->ar_size);
-       return (TRUE);
-}
-
-/*
- * Copy size bytes from current position if srcFd to current position in dstFd
- * taken from tarExtractRegularFile in tar.c, remove later
- */
-static int copySubFile(int srcFd, int dstFd, int copySize)
-{
-       int readSize, writeSize, doneSize;
-       char buffer[BUFSIZ];
-
-       while (copySize > 0) {
-               if (copySize > BUFSIZ)
-                       readSize = BUFSIZ;
-               else
-                       readSize = copySize;
-               writeSize = fullRead(srcFd, buffer, readSize);
-               if (writeSize <= 0) {
-                       errorMsg(io_error, "copySubFile :", strerror(errno));
-                       return (FALSE);
+               
+               entry->size = (size_t) atoi(raw_ar_header.size);
+               /* long filenames have '/' as the first character */
+               if (raw_ar_header.name[0] == '/') {
+                       if (raw_ar_header.name[1] == '/') {
+                               /* multiple long filenames are stored as data in one entry */
+                               long_name = (char *) xrealloc(long_name, entry->size);
+                               full_read(srcFd, long_name, entry->size);
+                               continue;
+                       }
+                       else {
+                               /* The number after the '/' indicates the offset in the ar data section
+                                       (saved in variable long_name) that conatains the real filename */
+                               const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
+                               entry->name = xmalloc(strlen(&long_name[long_name_offset]));
+                               strcpy(entry->name, &long_name[long_name_offset]);
+                       }
                }
-               doneSize = fullWrite(dstFd, buffer, writeSize);
-               if (doneSize <= 0) {
-                       errorMsg(io_error, "copySubFile :", strerror(errno));
-                       return (FALSE);
+               else {
+                       /* short filenames */
+                       entry->name = xmalloc(16);
+                       strncpy(entry->name, raw_ar_header.name, 16);
                }
-               copySize -= doneSize;
+               entry->name[strcspn(entry->name, " /")]='\0';
+
+               /* convert the rest of the now valid char header to its typed struct */ 
+               parse_mode(raw_ar_header.mode, &entry->mode);
+               entry->mtime = atoi(raw_ar_header.date);
+               entry->uid = atoi(raw_ar_header.uid);
+               entry->gid = atoi(raw_ar_header.gid);
+               entry->offset = lseek(srcFd, 0, SEEK_CUR);
+
+               /* add this entries header to our combined list */
+               entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+               *entry->next = *head;
+               *head = *entry;
+               lseek(srcFd, (off_t) entry->size, SEEK_CUR);
        }
-       return (TRUE);
+       return(*head);
 }
 
-/*
- * Extract the file described in ArInfo to the specified path 
- * set the new files uid, gid and mode 
- */
-static int extractToFile(struct ArInfo *file, int funct, int srcFd, const char *path)
-{
-       int dstFd, temp;
-       struct stat tmpStat;
-       char *pathname = NULL;
-       struct utimbuf newtime;
-       
-       if ((temp = isDirectory(path, TRUE, &tmpStat)) != TRUE) {
-               if (!createPath(path, 0777)) {
-                       fatalError("Cannot extract to specified path");
-                       return (FALSE);
-               }
-       }
-       temp = (strlen(path) + 16);
-       pathname = (char *) xmalloc(temp);
-       pathname = strcpy(pathname, path);
-       pathname = strcat(pathname, file->name);
-       dstFd = device_open(pathname, O_WRONLY | O_CREAT);
-       temp = copySubFile(srcFd, dstFd, file->size);
-       fchown(dstFd, file->uid, file->gid);
-       fchmod(dstFd, file->mode);
-       close(dstFd);
-       if ((funct&AR_PRESERVE_DATE)==AR_PRESERVE_DATE) 
-               newtime.modtime=file->date;
-       else
-               newtime.modtime=time(0);
-       newtime.actime=time(0);
-       temp = utime(pathname, &newtime);
-       return (TRUE);
-}
-
-/*
- * Return a file descriptor for the specified file and do error checks
- */
-static int getArFd(char *filename)
-{
-        int arFd;
-        char arVersion[8];
-
-        arFd = open(filename, O_RDONLY);
-        if (arFd < 0) { 
-                errorMsg("Error opening '%s': %s\n", filename, strerror(errno));
-               return (FALSE);
-       }
-        if (fullRead(arFd, arVersion, 8) <= 0) {
-                errorMsg( "ar: Unexpected EOF in archive\n");
-                return (FALSE);
-        }
-        if (strncmp(arVersion,"!<arch>",7) != 0) {
-                errorMsg("ar header fails check ");
-                return(FALSE);
-        }
-        return arFd;
-}
-
-/*
- * Step through the ar file and process it one entry at a time
- * fileList[0] is the name of the ar archive
- * fileList[1] and up are filenames to extract from the archive
- * funct contains flags to specify the actions to be performed 
- */
-static int readArFile(char *fileList[16], int fileListSize, int funct)
+extern int ar_main(int argc, char **argv)
 {
-       int arFd, status, extFileFlag, i, lastOffset=0;
-       ArHeader rawArHeader;
-       ArInfo arEntry;
-
-       /* open the ar archive */
-       arFd=getArFd(fileList[0]);
+       const int preserve_date = 1;    /* preserve original dates */
+       const int verbose = 2;          /* be verbose */
+       const int display = 4;          /* display contents */
+       const int extract_to_file = 8;  /* extract contents of archive */
+       const int extract_to_stdout = 16;       /* extract to stdout */
 
-       /* read the first header, then loop until ono more headers */ 
-       while ((status = fullRead(arFd, (char *) &rawArHeader, AR_BLOCK_SIZE))
-                  == AR_BLOCK_SIZE) {
+       int funct = 0, opt=0;
+       int srcFd=0, dstFd=0;
 
-               /* check the header is valid, if not try reading the header
-                  agian with an offset of 1, needed as some ar archive end
-                   with a '\n' which isnt counted in specified file size */
-               if ((status=processArHeader(&rawArHeader, &arEntry))==FALSE ) {
-                       if ((i=lseek(arFd, 0, SEEK_CUR))==(lastOffset+60)) 
-                               lseek(arFd, lastOffset+1, SEEK_SET);
-                       else 
-                               return(FALSE);
-                       }
-               else {  
-                       extFileFlag=0;
-                       
-                       if (funct&AR_DISPLAY) 
-                               displayEntry(&arEntry, funct);
+       ar_headers_t head, *extract_list=NULL;
 
-                       /* check file was specified to be extracted only if 
-                          some file were specified */
-                       if ((funct&AR_EXT_TO_FILE) || (funct&AR_EXT_TO_STDOUT)){
-                               if (fileListSize==1)
-                                       extFileFlag=1;
-                               else {
-                                       for( i=1; i<=fileListSize; i++)
-                                               if ((status=(strcmp(fileList[i],arEntry.name)))==0)
-                                                       extFileFlag=1;
-                               }
-                       }
-                       if (extFileFlag==1) { 
-                               if (funct&AR_EXT_TO_FILE)
-                                               extractToFile(&arEntry, funct, arFd, "./");
-                               else    
-                                               copySubFile(arFd,fileno(stdout),arEntry.size);
-                       }
-                       else
-                               lseek(arFd, arEntry.size, SEEK_CUR);
-                       lastOffset=lseek(arFd, 0, SEEK_CUR);
-               } /* if processArHeader */
-       }  /* while */
-       return (TRUE);
-}
+       extract_list = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
 
-extern int ar_main(int argc, char **argv)
-{
-        int funct = 0, ret=0, i=0;
-        char *fileList[16], c, *opt_ptr;
-
-       if (argc < 2)
-               usage(ar_usage);
-
-       opt_ptr = argv[1];
-       if (*opt_ptr == '-')
-               ++opt_ptr;
-       while ((c = *opt_ptr++) != '\0') {
-               switch (c) {
+       while ((opt = getopt(argc, argv, "ovtpx")) != -1) {
+               switch (opt) {
                case 'o':
-                       funct = funct | AR_PRESERVE_DATE;
+                       funct |= preserve_date;
                        break;
                case 'v':
-                       funct = funct | AR_VERBOSE;
+                       funct |= verbose;
                        break;
                case 't':
-                       funct = funct | AR_DISPLAY;
-                       break;
-               case 'x':
-                       funct = funct | AR_EXT_TO_FILE;
+                       funct |= display;
                        break;
                case 'p':
-                       funct = funct | AR_EXT_TO_STDOUT;
+                       funct |= extract_to_stdout;
+                       break;
+               case 'x':
+                       funct |= extract_to_file;
                        break;
                default:
                        usage(ar_usage);
                }
        }
-
-        for(i=0; i<(argc-2); i++) 
-                fileList[i]=argv[i+2];
+       /* check the src filename was specified */
+       if (optind == argc)
+               usage(ar_usage);
        
-       if (funct > 3)
-               ret = readArFile(fileList, (argc-2), funct);
+       if ( (srcFd = open(argv[optind], O_RDONLY)) < 0)
+               error_msg_and_die("Cannot read %s", argv[optind]);
+
+       optind++;       
+       head = get_headers(srcFd);
+
+       /* find files to extract or display */
+       /* search through argv and build extract list */
+       for (;optind<argc; optind++) {
+               ar_headers_t *ar_entry;
+               ar_entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+               ar_entry = &head;
+               while (ar_entry->next != NULL) {
+                       if (strcmp(argv[optind], ar_entry->name) == 0) {
+                               ar_headers_t *tmp;
+                               tmp = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+                               *tmp = *extract_list;
+                               *extract_list = *ar_entry;
+                               extract_list->next = tmp;
+                               break;                                  
+                       }
+                       ar_entry=ar_entry->next;
+               }
+       }
+
+       /* if individual files not found extract all files */   
+       if (extract_list->next==NULL) {
+               extract_list = &head;
+       }
        
-       return (ret);
+       /* find files to extract or display */  
+       while (extract_list->next != NULL) {
+               if (funct & extract_to_file) {
+                       dstFd = open(extract_list->name, O_WRONLY | O_CREAT, extract_list->mode);                               
+               }
+               else if (funct & extract_to_stdout) {
+                       dstFd = fileno(stdout);
+               }
+               if ((funct & extract_to_file) || (funct & extract_to_stdout)) {
+                       lseek(srcFd, extract_list->offset, SEEK_SET);
+                       copy_file_chunk(srcFd, dstFd, (size_t) extract_list->size);                     
+               }
+               if (funct & verbose) {
+                       printf("%s %d/%d %8d %s ", mode_string(extract_list->mode), 
+                               extract_list->uid, extract_list->gid,
+                               extract_list->size, time_string(extract_list->mtime));
+               }
+               if ((funct & display) || (funct & verbose)){
+                       printf("%s\n", extract_list->name);
+               }
+               extract_list=extract_list->next;
+       }
+       return EXIT_SUCCESS;
 }