git-logur : get log of GitHub repository without cloning. Shell script in bash for git log using GitHub API.

git-logur

#!/usr/bin/env bash
#              bash 4.3.11(1)   Linux 3.13.0   git 1.9.1      Date : 2018-01-12
#
# _______________|  git-logur : get log of GitHub repo without cloning.
#
#           Usage:  $ git-logur [username] [repository] [-m|-c|-v]
#                   #  Format defaults to messages -m, else
#                   #  -c for concise text, or -v for verbose json.
#                   #  Concise includes author and committer, with timestamps.
#
#         Example:  $ ./git-logur pydata pandas-datareader -c
#                   #  Outputs log as paragraphs in text format.
#
#    Dependencies:  curl
#                   GitHub API v3 https://developer.github.com/v3/
#                      esp. https://developer.github.com/v3/repos/commits
#
#  CHANGE LOG  Latest version at https://git.io/logur
#  2018-01-12  Append ?per_page=100&page=1 which means last 100 commits.
#                 Message only format. Case format arg.
#  2018-01-11  First version.


#           _____ PREAMBLE_v3: settings, variables, and error handling.
#
LC_ALL=POSIX
#      locale means "ASCII, US English, no special rules, 
#      output per ISO and RFC standards." 
#      Esp. use ASCII encoding for glob and sorting characters. 
shopt -s   extglob
#     ^set extended glob for pattern matching.
shopt -s   failglob
#         ^failed pattern matching signals error.
set -e
#   ^errors checked: immediate exit if a command has non-zero status. 
set -o pipefail
#   ^exit status on fail within pipe, not (default) last command.
set -u
#   ^unassigned variables shall be errors.
#    Example of default VARIABLE ASSIGNMENT:  arg1=${1:-'foo'}

user=${1:-'pydata'}
repo=${2:-'pandas-datareader'}
format=${3:-'-m'}
pager=${PAGER:-'less'}


program=${0##*/}   #  similar to using basename
memf=$( mktemp /dev/shm/88_${program}_tmp.XXXXXXXXXX )
errf=$( mktemp /dev/shm/88_${program}_tmp.XXXXXXXXXX )


cleanup () {
     #  Delete temporary files, then optionally exit given status.
     local status=${1:-'0'}
     rm -f $memf $errf
     [ $status = '-1' ] ||  exit $status      #  thus -1 prevents exit.
} #--------------------------------------------------------------------
warn () {
     #  Message with basename to stderr.          Usage: warn "message"
     echo -e "\n !!  ${program}: $1 "  >&2
} #--------------------------------------------------------------------
die () {
     #  Exit with status of most recent command or custom status, after
     #  cleanup and warn.      Usage: command || die "message" [status]
     local status=${2:-"$?"}
     #  cat $errf >&2
     cleanup -1  &&   warn "$1"  &&  exit $status
} #--------------------------------------------------------------------
trap "die 'SIG disruption, but cleanup finished.' 114" 1 2 3 15
#    Cleanup after INTERRUPT: 1=SIGHUP, 2=SIGINT, 3=SIGQUIT, 15=SIGTERM
trap "die 'unhandled ERR via trap, but cleanup finished.' 116" ERR
#    Cleanup after command failure unless it's part of a test clause.
#
# _______________     ::  BEGIN  Script ::::::::::::::::::::::::::::::::::::::::

#  Many API methods take optional parameters. For GET requests, any parameters
#  not specified as a segment in the path can be passed as an HTTP query string
#  parameter:
#  
#       curl "https://api.github.com/repos/vmg/redcarpet/issues?state=closed"
#  
#  In this example, the 'vmg' and 'redcarpet' values are provided for the :owner
#  and :repo parameters in the path while :state is passed in the query string.

api="https://api.github.com/repos/${user}/${repo}"


#  Parameter: "?per_page" 30 items on a page by default, 100 max.
#     We request multiple "?page=1", "?page=2", etc. and concatenate
#     them into memf. The last 200 commits seem sufficient.
curl -s "${api}/commits?per_page=100&page=1"            > $memf \
     &&  curl -s "${api}/commits?per_page=100&page=2"  >> $memf \
     ||  die "No connection to GitHub API using curl."  115



case "$format" in

        #  Message format adds newlines for text display, and provides URL/sha.
   -m)  grep -E '^    "sha":|"message":' $memf                               \
           |  sed -e 's/^ *//'  -e 's/,$//'  -e 's/"//g'                     \
                  -e "s/^message: //"  -e "s/\\\n/\n/g"  -e "s/\\\r//g"      \
              -e "s;^sha: ;---\nhttps://github.com/${user}/${repo}/commit/;" \
           |  $pager                                                         ;;


        #  Concise format includes author and committer, with respective dates.
   -c)  grep -E '^    "sha":|"login":|"date":|"message":' $memf              \
           |  sed -e 's/^ *//'  -e 's/,$//'  -e 's/"//g'                     \
              -e "s;^sha: ;---\nhttps://github.com/${user}/${repo}/commit/;" \
           |  $pager                                                         ;;


        #  CATCH-ALL is VERBOSE -v format.
    *)  $pager $memf                                                         ;;
esac

#       __________ Notes on concise format
#       Commit identifier "sha" of parents will not be shown.
#       Commit "sha" is converted to URL. Too many "html_url" json fields. 
#       Double "date" and "login": first for author, second for committer.
#       Username web-flow is GitHub, i.e. its web interface.
#       Add "---" between commits for paragraph effect.


#  Sample concise format, still with json crud, before sed edits:  
#       [Double labels: first, author; second, committer.]
#
#       "sha": "ddf71eff5c9752b2b9866756bac48b8307f58d5c",
#       "date": "2018-01-11T13:56:14Z"
#       "date": "2018-01-11T13:56:14Z"
#       "message": "Merge pull request #441 from bashtage/update-travis",
#       "login": "bashtage",
#       "login": "web-flow",
#       "sha": "bb3f4f45f7546023ff7e9f849c3f2638453b7f52",
#       "date": "2018-01-11T11:39:59Z"
#       "date": "2018-01-11T11:43:49Z"
#       "message": "BLD: Add versioneer to simplify versioning",
#       "login": "bashtage",
#       "login": "bashtage",


cleanup    #  Instead of: trap arg EXIT
# _______________ EOS ::  END of Script ::::::::::::::::::::::::::::::::::::::::


#       __________ List commits on a repository [Unused qualifiers]
#  
#       GET /repos/:owner/:repo/commits
#  
#  Parameter Type      Description
#  sha       string    SHA or branch to start listing commits from. 
#                          Default: repo’s default branch (usually master).
#  path      string    Only commits containing this file path will be returned.
#  author    string    GitHub login or email address of commit author.
#  since     string    Only commits after this date will be returned. 
#                          In ISO 8601 format: YYYY-MM-DDTHH:MM:SSZ.
#  until     string    Only commits before this date will be returned. 
#                          In ISO 8601 format: YYYY-MM-DDTHH:MM:SSZ.


#  vim: set fileencoding=utf-8 ff=unix tw=78 ai syn=sh :