[nmh] / uip / annosbr.c

/* annosbr.c -- prepend annotation to messages
 *
 * This code is Copyright (c) 2002, by the authors of nmh.  See the
 * COPYRIGHT file in the root directory of the nmh distribution for
 * complete copyright information.
 */

#include "h/mh.h"
#include "sbr/m_gmprot.h"
#include "sbr/cpydata.h"
#include "sbr/m_backup.h"
#include "sbr/error.h"
#include "h/tws.h"
#include "h/utils.h"
#include "sbr/lock_file.h"
#include "sbr/m_mktemp.h"
#include <fcntl.h>
#include <utime.h>


/*
 * static prototypes
 */
static int annosbr (int, char *, char *, char *, bool, bool, int, bool);

/*
 *      This "local" global and the annopreserve() function are a hack that allows additional
 *      functionality to be added to anno without piling on yet another annotate() argument.
 */

static  int     preserve_actime_and_modtime = 0;        /* set to preserve access and modification times on annotated message */

int
annotate (char *file, char *comp, char *text, bool inplace, bool datesw, int delete, bool append)
{
    int                 i, fd;
    struct utimbuf      b;
    struct stat         s;
    int                 failed_to_lock = 0;

    /* open and lock the file to be annotated */
    if ((fd = lkopendata (file, O_RDWR, 0, &failed_to_lock)) == NOTOK) {
        switch (errno) {
            case ENOENT:
                break;

            default:
                if (failed_to_lock) {
                    admonish (file, "unable to lock");
                } else {
                    admonish (file, "unable to open");
                }
                break;
        }
        return 1;
    }

    if (stat(file, &s) == -1) {
        inform("can't get access and modification times for %s", file);
        preserve_actime_and_modtime = 0;
    }

    b.actime = s.st_atime;
    b.modtime = s.st_mtime;

    i = annosbr (fd, file, comp, text, inplace, datesw, delete, append);

    if (preserve_actime_and_modtime && utime(file, &b) == -1)
        inform("can't set access and modification times for %s", file);

    lkclosedata (fd, file);
    return i;
}

/*
 *  Produce a listing of all header fields (annotations) whose field name matches
 *  comp.  Number the listing if number is set.  Treat the field bodies as path
 *  names and just output the last component unless text is non-NULL.  We don't
 *  care what text is set to.
 */

void
annolist(char *file, char *comp, char *text, int number)
{
    int         c;              /* current character */
    int         count;          /* header field (annotation) counter */
    char        *cp;            /* miscellaneous character pointer */
    char        *field;         /* buffer for header field */
    int         field_size;     /* size of field buffer */
    FILE        *fp;            /* file pointer made from locked file descriptor */
    int         length;         /* length of field name */
    int         n;              /* number of bytes written */
    char        *sp;            /* another miscellaneous character pointer */

    if ((fp = fopen(file, "r")) == NULL)
        adios(file, "unable to open");

    /*
     *  Allocate a buffer to hold the header components as they're read in.
     *  This buffer might need to be quite large, so we grow it as needed.
     */

    field = mh_xmalloc(field_size = 256);

    /*
     *  Get the length of the field name since we use it often.
     */

    length = strlen(comp);

    count = 0;

    do {
        /*
         *      Get a line from the input file, growing the field buffer as needed.  We do this
         *      so that we can fit an entire line in the buffer making it easy to do a string
         *      comparison on both the field name and the field body which might be a long path
         *      name.
         */

        for (n = 0, cp = field; (c = getc(fp)) != EOF; *cp++ = c) {
            if (c == '\n' && (c = getc(fp)) != ' ' && c != '\t') {
                (void)ungetc(c, fp);
                break;
            }

            if (++n >= field_size - 1) {
                field = mh_xrealloc((void *)field, field_size += 256);
                
                cp = field + n - 1;
            }
        }

        /*
         *      NUL-terminate the field..
         */

        *cp = '\0';

        if (strncasecmp(field, comp, length) == 0 && field[length] == ':') {
            for (cp = field + length + 1; *cp == ' ' || *cp == '\t'; cp++)
                ;

            if (number)
                (void)printf("%d\t", ++count);

            if (text == NULL && (sp = strrchr(cp, '/')))
                cp = sp + 1;

            puts(cp);
        }

    } while (*field != '\0' && *field != '-');

    /*
     *  Clean up.
     */

    free(field);

    (void)fclose(fp);
}

/*
 *      Set the preserve-times flag.  This hack eliminates the need for an additional argument to annotate().
 */

void
annopreserve(int preserve)
{
        preserve_actime_and_modtime = preserve;
}

static int
annosbr (int fd, char *file, char *comp, char *text, bool inplace, bool datesw, int delete, bool append)
{
    int mode, tmpfd;
    char *cp, *sp;
    char buffer[BUFSIZ], tmpfil[BUFSIZ];
    struct stat st;
    FILE        *tmp;
    int         c;              /* current character */
    int         count;          /* header field (annotation) counter */
    char        *field = NULL;  /* buffer for header field */
    int         field_size = 0; /* size of field buffer */
    FILE        *fp = NULL;     /* file pointer made from locked file descriptor */
    int         length;         /* length of field name */
    int         n;              /* number of bytes written */

    mode = fstat (fd, &st) != NOTOK ? (int) (st.st_mode & 0777) : m_gmprot ();

    if ((cp = m_mktemp2(file, "annotate", NULL, &tmp)) == NULL) {
        die("unable to create temporary file");
    }
    strncpy (tmpfil, cp, sizeof(tmpfil));
    chmod (tmpfil, mode);

    /*
     *  We're going to need to copy some of the message file to the temporary
     *  file while examining the contents.  Convert the message file descriptor
     *  to a file pointer since it's a lot easier and more efficient to use
     *  stdio for this.  Also allocate a buffer to hold the header components
     *  as they're read in.  This buffer is grown as needed later.
     */

    if (delete >= -1 || append) {
        if ((fp = fdopen(fd, "r")) == NULL)
            die("unable to fdopen file.");

        field = mh_xmalloc(field_size = 256);
    }

    /*
     *  We're trying to delete a header field (annotation )if the delete flag is
     *  not -2 or less.  A  value greater than zero means that we're deleting the
     *  nth header field that matches the field (component) name.  A value of
     *  zero means that we're deleting the first field in which both the field
     *  name matches the component name and the field body matches the text.
     *  The text is matched in its entirety if it begins with a slash; otherwise
     *  the text is matched against whatever portion of the field body follows
     *  the last slash.  This allows matching of both absolute and relative path
     *  names.  This is because this functionality was added to support attachments.
     *  It might be worth having a separate flag to indicate path name matching to
     *  make it more general.  A value of -1 means to delete all matching fields.
     */

    if (delete >= -1) {
        /*
         *  Get the length of the field name since we use it often.
         */

        length = strlen(comp);

        /*
         *  Initialize the field counter.  This is only used if we're deleting by
         *  number.
         */

        count = 0;

        /*
         *  Copy lines from the input file to the temporary file until we either find the one
         *  that we're looking for (which we don't copy) or we reach the end of the headers.
         *  Both a blank line and a line beginning with a - terminate the headers so that we
         *  can handle both drafts and RFC-2822 format messages.
         */

        do {
            /*
             *  Get a line from the input file, growing the field buffer as needed.  We do this
             *  so that we can fit an entire line in the buffer making it easy to do a string
             *  comparison on both the field name and the field body which might be a long path
             *  name.
             */

            for (n = 0, cp = field; (c = getc(fp)) != EOF; *cp++ = c) {
                if (c == '\n' && (c = getc(fp)) != ' ' && c != '\t') {
                    (void)ungetc(c, fp);
                    c = '\n';
                    break;
                }

                if (++n >= field_size - 1) {
                    field = mh_xrealloc((void *)field, field_size *= 2);
                
                    cp = field + n - 1;
                }
            }

            /*
             *  NUL-terminate the field..
             */

            *cp = '\0';

            /*
             *  Check for a match on the field name.  We delete the line by not copying it to the
             *  temporary file if
             *
             *   o  The delete flag is 0, meaning that we're going to delete the first matching
             *      field, and the text is NULL meaning that we don't care about the field body.
             *
             *   o  The delete flag is 0, meaning that we're going to delete the first matching
             *      field, and the text begins with a / meaning that we're looking for a full
             *      path name, and the text matches the field body.
             *
             *   o  The delete flag is 0, meaning that we're going to delete the first matching
             *      field, the text does not begin with a / meaning that we're looking for the
             *      last path name component, and the last path name component matches the text.
             *
             *   o  The delete flag is positive meaning that we're going to delete the nth field
             *      with a matching field name, and this is the nth matching field name.
             *
             *   o  The delete flag is -1 meaning that we're going to delete all fields with a
             *      matching field name.
             */

            if (strncasecmp(field, comp, length) == 0 && field[length] == ':') {
                if (delete == 0) {
                    if (text == NULL)
                        break;

                    for (cp = field + length + 1; *cp == ' ' || *cp == '\t'; cp++)
                        ;

                    if (*text == '/') {
                        if (strcmp(cp, text) == 0)
                                break;
                    }
                    else {
                        if ((sp = strrchr(cp, '/')) != NULL)
                            cp = sp + 1;

                        if (strcmp(cp, text) == 0)
                            break;
                    }
                }

                else if (delete == -1)
                        continue;

                else if (++count == delete)
                    break;
            }

            /*
             *  This line wasn't a match so copy it to the temporary file.
             */

            if ((n = fputs(field, tmp)) == EOF || (c == '\n' && fputc('\n', tmp) == EOF))
                die("unable to write temporary file.");

        } while (*field != '\0' && *field != '-');

        /*
         *  Get rid of the field buffer because we're done with it.
         */

        free(field);
    }

    else {
        /*
         *  Find the end of the headers before adding the annotations if we're
         *  appending instead of the default prepending.  A special check for
         *  no headers is needed if appending.
         */

        if (append) {
            /*
             *  Copy lines from the input file to the temporary file until we
             *  reach the end of the headers.
             */

            if ((c = getc(fp)) == '\n')
                rewind(fp);

            else {
                (void)putc(c, tmp);

                while ((c = getc(fp)) != EOF) {
                    (void)putc(c, tmp);

                    if (c == '\n') {
                        (void)ungetc(c = getc(fp), fp);

                        if (c == '\n' || c == '-')
                            break;
                    }
                }
            }
        }

        if (datesw)
            fprintf (tmp, "%s: %s\n", comp, dtimenow (0));
        if ((cp = text)) {
            do {
                while (*cp == ' ' || *cp == '\t')
                    cp++;
                sp = cp;
                while (*cp && *cp++ != '\n')
                    continue;
                if (cp - sp)
                    fprintf (tmp, "%s: %*.*s", comp, (int)(cp - sp), (int)(cp - sp), sp);
            } while (*cp);
            if (cp[-1] != '\n' && cp != text)
                putc ('\n', tmp);
        }
    }

    fflush (tmp);

    /*
     *  We've been messing with the input file position.  Move the input file
     *  descriptor to the current place in the file because the stock data
     *  copying routine uses the descriptor, not the pointer.
     */

    if (fp && lseek(fd, (off_t)ftell(fp), SEEK_SET) == (off_t)-1)
        die("can't seek.");

    cpydata (fd, fileno (tmp), file, tmpfil);
    fclose (tmp);

    if (inplace) {
        if ((tmpfd = open (tmpfil, O_RDONLY)) == NOTOK)
            adios (tmpfil, "unable to open for re-reading");

        lseek(fd, 0, SEEK_SET);

        /*
         *  We're making the file shorter if we're deleting a header field
         *  so the file has to be truncated or it will contain garbage.
         */

        if (delete >= -1 && ftruncate(fd, 0) == -1)
            adios(tmpfil, "unable to truncate.");

        cpydata (tmpfd, fd, tmpfil, file);
        close (tmpfd);
        (void) m_unlink (tmpfil);
    } else {
        strncpy (buffer, m_backup (file), sizeof(buffer));
        if (rename (file, buffer) == NOTOK) {
            switch (errno) {
                case ENOENT:    /* unlinked early - no annotations */
                    (void) m_unlink (tmpfil);
                    break;

                default:
                    admonish (buffer, "unable to rename %s to", file);
                    break;
            }
            return 1;
        }
        if (rename (tmpfil, file) == NOTOK) {
            admonish (file, "unable to rename %s to", tmpfil);
            return 1;
        }
    }

    /*
     *  Close the delete file so that we don't run out of file pointers if
     *  we're doing piles of files.  Note that this will make the close() in
     *  lkclose() fail, but that failure is ignored so it's not a problem.
     */

    if (fp)
        (void)fclose(fp);

    return 0;
}